MK-4827,(S)-2-(4-(piperidin-3-yl)phenyl)-2H-indazole-7-carboxaMide

1038915-60-4 CASfree form

1038915-64-8 CAS HYDROCHLORIDE

1613220-15-7 cas TOSYLATE MONOHYDRATE

MK-4827(Niraparib) tosylate is a selective inhibitor of PARP1/PARP2 with IC50 of 3.8 nM/2.1 nM; with great activity in cancer cells with mutant BRCA-1 and BRCA-2; >330-fold selective against PARP3, V-PARP and Tank1.
IC50 value: 3.8 nM/2.1 nM( PARP1/2) [1]
Target: PARP1/2
in vitro: MK-4827 displays excellent PARP 1 and 2 inhibition with IC(50) = 3.8 and 2.1 nM, respectively, and in a whole cell assay, it inhibits PARP activity with EC(50) = 4 nM and inhibits proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC(50) in the 10-100 nM range [1].
in vivo: MK-4827 is well tolerated in vivo and demonstrates efficacy as a single agent in a xenograft model of BRCA-1 deficient cancer [1]. In addition, MK-4827 strongly enhances the effect of radiation on a variety of human tumor xenografts, both p53 wild type and p53 mutant. The enhancement of radiation response is observed in clinically relevant radiation-dose fractionation schedules. The therapeutic window during which time MK-4827 interacts with radiation lasts for several hours. These biological attributes make translation of this therapeutic combination treatment feasible for translation to the treatment of a variety of human cancers [2].

[1]. Jones P, et al. Discovery of 2-{4-[(3S)-piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide (MK-4827): a novel oral poly(ADP-ribose)polymerase (PARP) inhibitor efficacious in BRCA-1 and -2 mutant tumors. J Med Chem. 2009 Nov 26;52(22):7170-85.

[2]. Wang L, et al. MK-4827, a PARP-1/-2 inhibitor, strongly enhances response of human lung and breast cancer xenografts to radiation. Invest New Drugs. 2012 Dec;30(6):2113-20.

MERCK

TESARO

Niraparib (originally MK-4827)^[1] is an orally active^[2] small molecule PARP inhibitor being developed (by Tesaro) to treat ovarian cancer.

It is an inhibitor of PARP1 and PARP2.^[3]

Niraparib is due to be submitted for FDA approval (for maintenance therapy in ovarian cancer) later in 2016.^[4]

Chemically, MK-4827 is C₁₉H₂₀N₄O^[5] (ignoring a possible tosylate group).^[6]

A 2012 study found that PARP inhibitors exhibit cytotoxic effects not based solely on their enzymatic inhibition of PARP, but by their trapping of PARP on damaged DNA, and the strength of this trapping activity was ordered niraparib >> olaparib >> veliparib.^[7]

NMR CD3OD

Clinical trials

It has undergone a phase III trial for ovarian cancer.^[8] It is reported that the primary endpoint (progression-free survival, PFS) was met.^[4] Patients with and without a BRCA mutation both showed longer PFS.^[4]

As of June 2016 seven clinical trials have been registered for MK-4827.^[9]

PAPER

http://pubs.acs.org/doi/abs/10.1021/op400233z

Process Development of C–N Cross-Coupling and Enantioselective Biocatalytic Reactions for the Asymmetric Synthesis of Niraparib

Abstract

Process development of the synthesis of the orally active poly(ADP-ribose)polymerase inhibitor niraparib is described. Two new asymmetric routes are reported, which converge on a high-yielding, regioselective, copper-catalyzed N-arylation of an indazole derivative as the late-stage fragment coupling step. Novel transaminase-mediated dynamic kinetic resolutions of racemic aldehyde surrogates provided enantioselective syntheses of the 3-aryl-piperidine coupling partner. Conversion of the C–N cross-coupling product to the final API was achieved by deprotection and salt metathesis to isolate the desired crystalline salt form.

PAPER

 as tosylate H20

1613220-15-7 cas

Free form 1038915-60-4

• 2-[4-(3S)-3-Piperidinylphenyl]-2H-indazole-7-carboxamide
• Niraparib
•  Jones, Philip; Journal of Medicinal Chemistry 2009, V52(22), P7170-7185
• MK-4827

(S)-2-(4-(Piperidin-3-yl)phenyl)-2H-indazole-7-carboxamide Tosylate Monohydrate 1

Discovery of 2-{4-[(3S)-Piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide (MK-4827): A Novel Oral Poly(ADP-ribose)polymerase (PARP) Inhibitor Efficacious in BRCA-1 and -2 Mutant Tumors

Philip Jones*, Sergio Altamura, Julia Boueres, Federica Ferrigno, Massimiliano Fonsi, Claudia Giomini, Stefania Lamartina, Edith Monteagudo, Jesus M. Ontoria, Maria Vittoria Orsale, Maria Cecilia Palumbi, Silvia Pesci, Giuseppe Roscilli, Rita Scarpelli, Carsten Schultz-Fademrecht, Carlo Toniatti and Michael Rowley

IRBM/Merck Research Labs Rome, Via Pontina km 30,600, 00040 Pomezia, Italy

J. Med. Chem., 2009, 52 (22), pp 7170–7185

DOI: 10.1021/jm901188v, http://pubs.acs.org/doi/abs/10.1021/jm901188v?source=chemport

*To whom correspondence should be addressed. Current address: Department of Medicinal Chemistry, Merck Research Labs Boston, Avenue Louis Pasteur 33, Boston, MA 02115-5727. Phone: +1-617-992-2292. Fax: +1-617-992-2405. E-mail: philip_jones@merck.com.

Abstract

We disclose the development of a novel series of 2-phenyl-2H-indazole-7-carboxamides as poly(ADP-ribose)polymerase (PARP) 1 and 2 inhibitors. This series was optimized to improve enzyme and cellular activity, and the resulting PARP inhibitors display antiproliferation activities against BRCA-1 and BRCA-2 deficient cancer cells, with high selectivity over BRCA proficient cells. Extrahepatic oxidation by CYP450 1A1 and 1A2 was identified as a metabolic concern, and strategies to improve pharmacokinetic properties are reported. These efforts culminated in the identification of 2-{4-[(3S)-piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide 56 (MK-4827), which displays good pharmacokinetic properties and is currently in phase I clinical trials. This compound displays excellent PARP 1 and 2 inhibition with IC₅₀ = 3.8 and 2.1 nM, respectively, and in a whole cell assay, it inhibited PARP activity with EC₅₀ = 4 nM and inhibited proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC₅₀ in the 10−100 nM range. Compound 56 was well tolerated in vivo and demonstrated efficacy as a single agent in a xenograft model of BRCA-1 deficient cancer.

PATENT

https://www.google.com/patents/WO2014088983A1?cl=en

EXAMPLE 1

The following Example 1 describes synthesis of the compound 2-{4-[(3S)-Piperidin enyl}-2H-indazole-7-carboxamide:

2-{4-[(3S)-Piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide tosylate monohydrate 1

Scheme

1.1 Acylation

2- crystalline

10

A mixture of succinic anhydride 1 (110 g) and bromobenzene (695 mL) was cooled to below 5°C then added A1C1₃ (294 g). The slurry was allowed to warm to RT and then aged until the reaction was complete judged by HPLC. The reaction mixture was then transferred slowly into a cold HC1 solution resulting in the formation of a white precipitate. The white slurry was filtered through a fritted funnel rinsing with H₂0. To the off-white product was added MTBE and extracted with aq. NaOH. The aqueous layer was cooled in an ice bath. Concentrated HC1 was added drop wise to adjust the solution pH to 1 , resulting in the formation of a white slurry. The slurry was collected on a fritted funnel, rinsed with H₂0, and dried under vacuum with a N₂ sweep at RT to give the target compound (265 g, 93% corrected yield) as a white powder.

1.2 Esterification

A mixture of the acid 2 (205 g), IPA (4 L) and cone. H₂S0₄ (2.13 mL / 3.91 g) was heated to a gentle reflux until the reaction was complete judged by HPLC. The solution was then cooled to RT and concentrated to a volume of 350-400 mL. The residue was dissolved in

MTBE (1.2 L), washed with aq. Na₂C0₃ followed by water. After dried over MgS0₄ , the filtrate was solvent-switched into heptane. The slurry was then filtered, and the cake was washed with cold heptane. After drying under vacuum, the target compound (223.5 g, 93% corrected yield) was obtained as a white powder.

1.3 Epoxidation

A mixture of Me₃SOI (230 g) and DMSO (300 mL) was added KOt-Bu (113 g) followed by DMSO (300 mL). The mixture was aged for a further 1.5 hr. In a separate flask, ketone 3 (230 g) was dissolved in a mixture of THF (250 mL) and DMSO (150 mL), and the resulting solution was added drop wise to the ylide solution. The mixture was aged for 2 hr at RT, added hexanes (1 L), and then quenched by the addition of ice-water (600 mL). The layers were cut, and the organic layer was washed with water then with brine. The slightly cloudy yellow organic layer was dried over Na₂S0₄ and filtered through a fritted funnel. Product solution assay was 176.1 g (76%> assay yield). This solution was carried forward into the rearrangement step. 1.4 Epoxide rearrangement and bisulfite formation

5 – not isolated

A solution of crude epoxide 4 (assay 59.5 g) in hexanes was solvent switched into PhMe, and added ZnBr₂ (10.7 g). When the rearrangement was complete judged by HPLC, the slurry was filtered through a fritted funnel. The clear filtrate was washed with 10% aq. NaCl and then stirred with a solution of sodium bisulfite (NaHS0₃, 24.7 g) in H₂0 (140 mL) vigorously at RT for 3 hr. The cloudy aqueous layer was separated and washed with heptanes. By 1H-NMR assay, the aqueous solution contained 71.15 g bisulfite adduct 6 (30.4 wt % solution, 90%) yield from crude epoxide 4). This solution was used directly in the subsequent transaminase step.

1.5 Transaminase DKR

45 C, inert, 40-46 hrs 7

100 g/L as 17.16 wt % aq solution 99.3% ee

85-87% yield

To a cylindrical Labfors reactor was charged pyridoxal-5 -phosphate (1.4 g, 5.66 mmol), 452 ml 0.2 M borate buffer pH 10.5 containing 1M iPrNH₂, 52 g transaminase (SEQ ID NO: 180), and 75 ml DMSO, and the resulting mixture was warmed to 45°C. The pH was controlled at pH 10.5 using 8 M aq iPrNH₂. To this was added dropwise a mixture of 17.16 wt% aq solution of ester bi-sulfite 6 (147.2 g, 353 mmol) and 219 ml DMSO under N₂ atmosphere. When the reaction was complete judged by HPLC, the reaction mixture was cooled and extracted with 1 volume of 3:2 IPA:IPAc. The aq/rag layer was extracted again with 1 volume of 3:7 IPATPAc. The organic layer was washed with brine at pH >9. Assay yield in solution was 78 g (87%); 99.3% ee. After dried over MgS0₄, and filtered through a fritted funnel, the crude solution was concentrated under vacuum flushing with IP Ac to remove IPA. The resulting slurry was concentrated to a final volume of -200 mL, cool to below 0°C, and filtered to collect the solid. The cake was washed with ice-cold IPAc and dried at RT under vacuum to give the desired product (84% corrected yield, 99.3 LCAP) as a white powder. 1.6. Reduction of amide

(S)-3-(4-bromophenyl)piperidine

The lactam 7 can be reduced to form the i eridine 8 as described below:

7 – crystalline

A mixture of lactam 7 (10.25 g at 97.5 wt %) in THF (100 mL) was cooled to < 10°C, and added NaBH₄ (4.47 g). EtOH (6.89 mL) was then added slowly over 20 min. The slurry was aged for an additional 1 hr at 2°C after which BF₃ THF (13.03 mL) was added over 1 hr. The slurry was slowly warmed to RT and aged until complete conversion judged by HPLC. The reaction was then cooled to < 5°C then slowly quenched with MeOH (7.96 mL), added HC1 (9.69 mL), then the reaction was heated to 45°C until decomplexation of product-borane complex was complete, as indicated by LC assay. The reaction was cooled, diluted with IPAc (75 mL) and water (80 mL), and then pH was adjusted with aqueous NH₄OH to pH 8. The organic layer was separated, added 75 mL water, then pH adjusted to 10.5 with 50 wt % NaOH. The layers were separated and the organic layer was washed with brine. After solvent-switched to IPAc, LC Assay yield was 9.1g; 95.9%.

1.7 Tosylate salt formation The tosylate salt of the piperidine 8 can be formed as described below:

The crude piperidine 8 free base in IPA was heated to ~40°C. TsOH H₂0 solids was added portion-wise. The slurry was warmed to 50°C and held at that temperature for 2 h, and then slowly cooled to RT and aged overnight. Supernatant concentration was measured to be 2.5 g/ml (free base concentration). The solids were filtered and washed with IP Ac (3×15 mL) and dried at RT. Isolated solides: 14.85 g, 96% corrected isolated yield.

1.8 Boc protection

The piperi ine 8 tosylate salt can be protected as described below:

To a stirred slurry of the tosylate salt of piperidine 8 (25.03 g, 60.6 mmol) in MTBE (375 ml) was added NaOH (aq. 1.0 N, 72.7 ml, 72.7 mmol) at RT. To the mixture, (BOC)₂0 (13.36 ml, 57.6 mmol) was added slowly over 3 min. The resulting mixture was stirred for 4.5 hr at RT, and then the aqueous layer was separated. The MTBE layer was washed with water (100 ml X 2). The organic layer was filtered, and DMAC (100 ml) was added to the filtrate and

concentrated under vacuum. Product assay: 21.86 g, quantitative yield.

1.9 Terf-Butylamide Formation

N-(tert-butyl)- 1 H-indazole-7-carboxamide

10 11

Indazole-7-carboxylic acid 10 (50.3 g, 295 mmol) was dissolved in DMF, and added CDI (59.1 g, 354 mmol) at RT. After 1.5hr, tert-butylamine (62.5 ml, 589 mmol) was added to the reaction mixture. The resulting reaction mixture was warmed to 40 °C until complete

conversion, then cooled to RT. Water (600 ml) was added dropwise causing the mixture to form a thick slurry. Solid was collected by filtration and washed with 10% DMF in water (250 ml) followed by water. The solid was dried under vacuum. Beige solid: 55.31 g, 86%> isolated yield.

1.10 Carbon-Nitrogen Coupling

(S)-tert-butyl 3-(4-(7-(tert-butylcarbamoyl)-2H-indazol-2-yl)phenyl)piperidine- 1 -carboxylate

A mixture of the protected piperidine 9 (113 g, 18.23 wt%, 60.6 mmol) in DMAc (160 mL), compound 11 (13.82 g, 63.6 mmol), and K₂CO₃ (25.6 g, 182 mmol) was degassed by bubbling nitrogen. To the mixture was added CuBr (0.444 g, 3.03 mmol) and 8- hydroxyquinoline 12 (0.889 g, 6.06 mmol), and the resulting mixture was warmed to 110°C until complete conversion. The reaction mixture was then cooled, filtered through a pad of Celite, and rinsed with DMAc (100 ml). The filtrate was warmed to 35°C and added citric acid aqueous solution (10%) dropwise to form a light green slurry. After cooled to room temperature, the slurry was filtered, and the cake was washed with DMAc/Water (2/1, 150ml) followed by copious amount of water. The solid was dried under vacuum with nitrogen. Net weight: 27.24g. LC assay: 26.77g, 98.3 wt %. Assay yield: 93.6%.

1.11 Double deprotection

To compound 13 (20.0 g, 41.2 mmol) was added MSA (60 ml) and o-xylene (40 ml), and the the reaction mixture was warmed to 40°C until the complete conversion judged by HPLC. The reaction mixture was cooled to RT and added water (140 ml) slowly maintaining the temperature < 25°C. When the water addition was completed, the organic layer was removed, and the aq. layer was washed with toluene. The aqueous layer was filtered through a glass funnel, and the filtrate was added an aqueos solution of TsOH (11.77g in 23.5 ml) slowly at RT causing a thick slurry to form. Solid was collected by filtration, washed with water, and dried under vacuum. The titled compound was obtained as a white powder. Net weight: 20.6 g. LC assay: 20.0 g, 97.3 wt %. Assay yield: 95.2%.

EXAMPLE 2

The following Example 2 describes synthesis of the trifluoromethylacetate salt of compound 2-{4-[(3S)-Piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide:

2.1 Cumylamide Formation

N-(2-phenylpropan-2-yl)- 1 H-indazole-7-carboxamide

10 1 5

10

To the indazole-7-carboxylic acid 10 (400 mg, 2.47 mmol) in tetrahydrofuran (9.9 mL), was sequentially added HATU (1.13 g, 2.96 mmol), DIPEA (2.15 mL, 12.3 mmol), and cumylamine (500 mg, 3.70 mmol) at 50°C. The reaction was stirred overnight before being concentrated and loaded directly onto a silica column, eluting with 10-30% EtOAc/hexane. The product was collected and concentrated to afford the desired product as a colorless solid (557 mg, 81% yield).

2.2 Carbon-Nitrogen Coupling

-butyl 3-(4-(7-((2-phenylpropan-2-yl)carbamoyl)-2H-indazol-2-yl)phenyl)piperidine- carboxylate

15 16

A sealed vial containing the indazole-7-carboxamide 15 (50 mg, 0.18 mmol), copper(I) iodide (2.6 mg, 0.014 mmol), potassium phosphate tribasic (80 mg, 0.38 mmol), and aryl bromide 9 (73.1 mg, 0.215 mmol) was evacuated and backfilled with argon (x3). Trans-N,N’- dimethylcyclohexane-l,2-diamine (11.3 μΐ,, 0.072 mmol), and toluene (179 μΐ) were then added successively and the sealed vial was heated at 110 °C overnight. The vial was then cooled and toluene (0.30 mL) was added to the slurry. Crude LC/MS indicated >20: 1 selectivity for the desired indazole isomer. The crude product was purified by loading directly onto a Biotage Snap 10G silica column, eluting with 5-50% EtOAc/hexane. The product was collected and concentrated to afford the desired product as a colorless solid (78 mg, 81% yield).

2.3 Double deprotection

(5)-2-(4-(piperidin-3-yl)phenyl)-2H-indazole-7-carboxamide trifluoromethylacetate salt

16 17

To the piperidine-l-carboxylate 16 (45 mg, 0.084 mmol), was added triethylsilane (267 μί, 1.67 mmol) and TFA (0.965 mL, 12.5 mmol) at 25°C. The reaction was stirred for 4 hours and the reaction was concentrated in vacuo, and purified by mass triggered reverse phase HPLC (acetonitrile: water, with 0.1% TFA modifier). Lyphilization gave the desired product as the TFA salt and as a white solid (31 mg, 85% yield). HRMS (ESI) calc’d for Ci₉H₂iN₄0 [M+H]⁺: 321.1710, found 321.1710.

EXAMPLE 3

Following the conditions used in sections 2.1 and 2.2 of Example 2, this Example 3 shows regioselective N2 arylation of compound 9 using various amide protecting groups. The indazole-7-carboxylic acid 10 was reacted with various amines to generate a protected amide.

The amide protecting groups are indicated by the R group in Table 2. The amide coupling yield is provided in Table 2. The Cu-mediated carbon-nitrogen coupling of this indazole to compound 9 was then tested to determine if regioselective N2 arylation was possible. The arylation yield is also provided in Table 2. The data shows that various amide protecting groups on the indazole intermediate are suitable to generate efficient regioselective N2 arylation of compound 9.

PATENT CITATIONS

Cited Patent	Filing date	Publication date	Applicant	Title
US8071623 *	Jan 8, 2008	Dec 6, 2011	Instituto Di Ricerche Di Biologia Molecolare P. Angeletti Spa	Amide substituted indazoles as poly(ADP-ribose)polymerase(PARP) inhibitors
US8129377 *	Sep 29, 2005	Mar 6, 2012	Mitsubishi Tanabe Pharma Corporation	6-(pyridinyl)-4-pyrimidone derivates as tau protein kinase 1 inhibitors
US20100286203 *	Jan 8, 2009	Nov 11, 2010	Foley Jennifer R	Pharmaceutically acceptable salts of 2–2h-indazole-7-carboxamide

* Cited by examiner

NON-PATENT CITATIONS

Reference
1	*	CHUNG ET AL.: “Process Development of C-N Cross-Coupling and Enantioselective Biocatalytic Reactions for the Asymmetric Synthesis of Niraparib.“, ORGANIC PROCESS RESEARCH & DEVELOPMENT, vol. 18, no. 1, 2014, pages 215 – 227, XP055263728
2	*	JONES ET AL.: “Discovery of 2-(4-[(3S)-Piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide ( MK -4827): A Novel Oral Poly(ADP-ribose)polymerase (PARP) Inhibitor Efficacious in BRCA-1 and -2 Mutant Tumors.“, JOURNAL OF MEDICINAL CHEMISTRY, vol. 52, no. 22, 2009, pages 7170 – 7185, XP055263725
3	*	WALLACE ET AL.: “Development of a Fit-for-Purpose Large-Scale Synthesis of an Oral PARP Inhibitor.“, ORGANIC PROCESS RESEARCH & DEVELOPMENT, vol. 15, no. 4, 2011, pages 831 – 840, XP055263721

* Cited by examiner

REFERENCED BY

Citing Patent	Filing date	Publication date	Applicant	Title
WO2016025359A1 *	Aug 10, 2015	Feb 18, 2016	Merck Sharp & Dohme Corp.	Processes for the preparation of a bace inhibitor

References

1. Jump up^ “PARP Inhibitors in Oncology. Chemosensitizers or Single-Agent Therapeutics?” (PDF). July 2009.
2. Jump up^ A Phase III Trial of Niraparib Versus Physician’s Choice in HER2 Negative, Germline BRCA Mutation-positive Breast Cancer Patients (BRAVO)
3. Jump up^ “PARP inhibitor, MK-4827, shows anti-tumor activity in first trial in humans”. 17 Nov 2010.
4. ^ Jump up to:^{a b c} Tesaro’s PARP ovarian cancer drug hits PhIII goal; prepares to file. June 2016
5. Jump up^ MK-4827 @ pubchem
6. Jump up^ MK-4827
7. Jump up^ Murai, Junko, et al. “Trapping of PARP1 and PARP2 by clinical PARP inhibitors.” Cancer research 72.21 (2012): 5588-5599.
8. Jump up^ AbbVie takes PARP inhibitor into third phase III trial. June 2014
9. Jump up^ Niraparib studies

Further reading

• The poly(ADP-ribose) polymerase inhibitor niraparib (MK4827) in BRCA mutation carriers and patients with sporadic cancer: a phase 1 dose-escalation trial.(NCT00749502)

Niraparib

Clinical data
Routes of administration	By mouth
Legal status
Legal status	US: Investigational
Identifiers
IUPAC name[show]
CAS Number	1038915-60-4
PubChem (CID)	24958200
ChemSpider	24531930
UNII	HMC2H89N35
ChEMBL	CHEMBL1094636
Chemical and physical data
Formula	C19H20N4O
Molar mass	320.394 g/mol
3D model (Jmol)	Interactive image
SMILES[hide] c1cc2cn(nc2c(c1)C(=O)N)c3ccc(cc3)[C@@H]4CCCNC4

FDA approves first drug for spinal muscular atrophy

New therapy addresses unmet medical need for rare disease

The U.S. Food and Drug Administration today approved Spinraza (nusinersen), the first drug approved to treat children and adults with spinal muscular atrophy (SMA), a rare and often fatal genetic disease affecting muscle strength and movement. Spinraza is an injection administered into the fluid surrounding the spinal cord.

Read more.

Centanafadine; UNII-D2A6T4UH9C; EB-1020 free base; D2A6T4UH9C; 924012-43-1

CTN SR; EB-1020; EB-1020 SR

WO 2007016155

• Phase II Attention-deficit hyperactivity disorder
• No development reported Major depressive disorder; Neuropathic pain

Most Recent Events

• 20 Dec 2016 Neurovance plans a phase III trial for Attention-deficit hyperactivity disorder
• 27 Jul 2016 Efficacy data from a phase IIb trial in Attention-deficit hyperactivity disorder released by Neurovance
• 16 Jul 2016 No recent reports of development identified for phase-I development in Attention-deficit-hyperactivity-disorder in Canada (PO)

• Originator Euthymics Bioscience
• Developer Euthymics Bioscience; Neurovance
• Class Azabicyclo compounds; Cyclohexanes; Naphthalenes; Small molecules
• Mechanism of Action Adrenergic uptake inhibitors; Dopamine uptake inhibitors; Serotonin uptake inhibitors

cas 923981-14-0 hydrochloride

(1R,5S)-1-(naphthalen-2-yl)-3-azabicyclo(3.1.0)hexane hydrochloride

Centanafadine (INN) (former developmental code name EB-1020) is a serotonin-norepinephrine-dopamine reuptake inhibitor (SNDRI) under development by Neurovance in collaboration with Euthymics Bioscience as a treatment for attention deficit hyperactivity disorder (ADHD) that inhibits the reuptake of norepinephrine, dopamine and serotonin with a ratio of 1:6:14, respectively.^[1][2][3] As of August 2015, it is in phase II clinical trials.[1]

Also claimed is their use for treating attention deficit hyperactivity disorder (ADHD), fragile-X associated disorder, autism spectrum disorder and depression. See WO2015089111, claiming method for treating fragile X-associated disorders, assigned to Neurovance, naming Piskorski, Bymaster and Mckinney. Neurovance, an affiliate of Euthymics Bioscience, is developing centanafadine, a sustained release formulation and a non-stimulant triple reuptake inhibitor, for treating ADHD and is also investigating the drug for treating neuropathic pain.

In June 2015, the drug was reported to be in phase 2 clinical and preclinical development for treating ADHD and neuropathic pain, respectively. Inventors are affiliated with Neurovance.

Attention-deficit hyperactivity disorder (ADHD) is a central nervous system

(CNS) disorder characterized by developmentally inappropriate inattention, hyperactivity, and impulsivity (Buitelaar et al., 2010; Spencer et al., 2007). ADHD is one of the most common developmental disorders in children with 5-10% prevalence (Scahill et al., 2000; Polanczyk et al., 2007). While ADHD was once regarded as only a childhood disorder, it can continue through adolescence and into adulthood. An estimated 2.9-4.4% of the adult population has continuing ADHD (Kessler et al., 2006; Faraone and Biederman, 2005). Major symptoms in adults include inattention, disorganization, lack of concentration and to some extent impulsivity, which result in difficulty functioning, low educational attainment, under achievement in vocational and educational pursuits, and poor social and family relations (Biederman et al, 2006; Barkely et al., 2006).

The exact causes of ADHD are not known, but a dysfunction of the prefrontal cortex and its associated circuitries has been posited as a key deficit in ADHD (Arnsten, 2009). Consistent with this notion is the finding that abnormal catecholaminergic function plays a key role, particularly in prefrontal cortical regions (Arnsten 2009). The

catecholamines norepinephrine (NE) and dopamine (DA) are highly involved in several domains of cognition including working memory, attention, and executive function. Accordingly, these monoamine neurotransmitters are believed to work in concert in modulating cognitive processes.

Pharmacotherapy is a primary form of treatment utilized to reduce the symptoms of ADHD. Stimulants such as methylphenidate and amphetamines are commonly used for ADHD. The major mechanism of action of the stimulants is inhibition of DA and NE transporters. The stimulants are effective against the core symptoms of ADHD and have a response rate of about 70% (Spencer et al. , 2005). However, major concerns about stimulants include risk of abuse, dependency, and diversion as well as potential neurotoxic effects of amphetamines (Berman et al., 2009). The abuse potential of stimulants is particularly problematic in adults because substance abuse is a common co-morbidity with adult ADHD (Levin and Kleber, 1995; Ohlmeier, 2008).

Another major drug used to treat ADHD is atomoxetine, which is a selective norepinephrine reuptake inhibitor. Major advantages of atomoxetine compared to the stimulants is lack of abuse potential, once-daily dosage, and superior treatment of comorbidities such as anxiety and depression. However, atomoxetine has lower efficacy and takes 2-4 weeks for onset of action (Spencer et al., 1998; Newcorn et al., 2008).

Accordingly, there remains a need for effective pharmaceuticals which may be used in the treatment of ADHD and other conditions affected by monoamine neurotransmitters.

PATENT

WO 2007016155

https://www.google.ch/patents/WO2007016155A2?hl=de&cl=en

Reaction Scheme 1 below generally sets forth an exemplary process for preparing l-aryl-3-azabicyclo[3.1.0] hexane analogs from the corresponding 2-bromo-2- arylacetate or 2-chloro-2-arylacetate. The bromo or chloro acetate react with acrylonitrile to provide the methyl 2-cyano-l-arylcyclopropanecarboxylate, which is then reduced to the amino alcohol by reducing agents such as lithium aluminum hydride (LAH) or sodium aluminum hydride (SAH) or NaBH₄ with ZnCl₂. Cyclization of the amino alcohol with SOCl₂ or POCl₃ will provide the l-aryl-3-azabicyclo[3.1.0]hexane. The cyclization of substituted 4-aminobutan-l -ol by SOCl₂ or POCl₃ into the pyrrolidine ring system was reported by Armarego et al, J. Chem. Soc. [Section C: Organic] 19:3222-9, (1971), and in Szalecki et al., patent publication PL 120095 B2, CAN 99:158251. Oxalyl chloride, phosphorous tribromide, triphenylphosphorous dibromide and oxalyl bromide may be used for the same purpose. The methyl 2-bromo-2 -arylacetate or methyl 2- chloro-2-arylacetate may be synthesized from subsituted benzoylaldehyde or methyl-2- arylacetate as shown in Reaction Scheme IA.

Reaction Scheme 1

Reduction

Reagents: (a) NaOMe; (b) LiAIH₄; (c) SOCI₂; (d) POCI₃; (e) NaOH or NH₃ H₂O

Reaction Scheme IA

Reagents: (a) CHCI₃, NaOH; (b) SOCI₂; (c) MeOH; (d) NaBrO₃, NaHSO₃ [00138] Reaction Scheme 2 below illustrates another exemplary process for transforming methyl 2-cyano-l-arylcyclopropanecarboxylate to a desired compound or intermediate of the invention. Hydrolysis of the cyano ester provides the potassium salt which can then be converted into the cyano acid. Reduction and cyclization of the 2- cyano-1-arylcyclopropanecarboxylic acid with LAH or LiAlH(OMe)₃according to the procedure outlined in Tetrahedron 45:3683 (1989), will generate l-aryl-3- azabicyclo[3.1.0]hexane. In addition, the cyano- 1-arylcyclopropanecarboxylic acid can be hydrogenated and cyclized into an amide, which is then reduced to l-aryl-3- azabicyclo[3.1.0]hexane.

Reaction Scheme 2

Hydrolysis

Reagents: (a) NaOMe; (b) KOH; (c) HCI; (d) LiAIH(OMe)₃, or LAH, or SAH, then HCI; (e) H₂/Pd or H₂/Ni

[00139] Reaction Scheme 3 below discloses an alternative exemplary process for converting the methyl 2-cyano-l-arylcyclopropanecarboxylate to a desired compound or intermediate of the invention. The methyl 2-cyano-l-arylcyclopropanecarboxylate is reduced and cyclized into l-aryl-3-aza-bicyclo[3.1.0]hexan-2~one, which is then reduced to l-aryl-3-azabicyclo[3.1.0]hexane [Marazzo, A. et al., Arkivoc 5:156-169, (2004)].

Reaction Scheme 3

Reagents: (a) H₂/Pd or H₂/Ni; (b) B₂H₆ or BH₃ or LAH, then HCI [00140] Reaction Scheme 4 below provides another exemplary process to prepare l-aryl-3-azabicyclo[3.1.0] hexane analogs. Reaction of 2-arylacetonitrile with (+)- epichlorohydrin gives approximately a 65% yield of 2-(hydroxyrnethyl)-l- arylcyclopropanecarbonitrile (85% cis) with the trans isomer as one of the by-products [Cabadio et al., Fr. Bollettino Chimico Farmaceutico 117:331-42 (1978); Mouzin et al., Synthesis 4:304-305 (1978)]. The methyl 2-cyano-l-arylcyclopropanecarboxylate can then be reduced into the amino alcohol by a reducing agent such as LAH, SAH or NaBH₄ with ZnCl₂ or by catalytic hydrogenation. Cyclization of the amino alcohol with SOCl₂ or POCl₃ provides the l-aryl-3-azabicyclo[3.1.0]hexane. The cyclization of substituted 4-aminobutan-l-ol by SOCl₂ or POCl₃ into the pyrrolidine ring system has been reported previously [Armarego et al., J. Chem. Soc. [Section C: Organic] 19:3222-9 (1971); patent publication PL 120095 B2, CAN 99:158251).

ϋv siυjiijJsoLJa

Reaction Scheme 4

Ar CN

ion

Reagents: (a) NaHMDS; (b) LAH or catalytic hydrogenation; (c) SOCl₂; (d) POCI₃; (e) NaOH

[00141] Reaction Scheme 5 provides an exemplary process for synthesizing the

(IR, 5S)-(+)-l-aryl-3-azabicyclo[3.1.0]hexanes. Using (S)-(+)-epichlorohydrin as a starting material in the same process described in Scheme 4 will ensure a final product with 1-R chirality [Cabadio, S. et al, Fr. Bollettino Chimico Farmaceutico 117:331-42 (1978)].

Reaction Scheme 5

ion

^Ar

H’..

Reagents: (a) NaHMDS; (b) LAH or catalytic hydroge nation; (c) SOCI₂; (d) POCl₃; (e) NaOH j_j

[00142] Reaction Scheme 6 provides an exemplary process to prepare the (1 S,5R)-

(-)-l-aryl-3-azabicyclo[3.1.0]hexanes. Using (R)-(-)-epichlorohydrin as a starting material in the same process described in Scheme 4 will ensure a final product with 1-S chirality [Cabadio, S. et al, Fr. Bollettino Chimico Farmaceutico 117:331-42 (1978)].

Reaction Scheme 6

Ar CN

c or d, Cyclization

Reagents: (a) NaHMDS; (b) LAH or catalytic hydrogenation; (C) SOCI₂; (d) POCI₃; (e) NaOH

[00143] Reaction Scheme 7 provides an alternative exemplary process for transforming the 2-(hydroxymethyl)-l-arylcyclopropanecarbonitrile to a desired compound or intermediate of the invention via an oxidation and cyclization reaction. Utilizing chiral starting materials (+)-epichlorohydrin or (-)-epichlorohydrin will lead to the corresponding (+)- or (-)-enantiomers and corresponding chiral analogs through the same reaction sequences.

Reaction Scheme 7

O Cyclopropanantion Oxidation

Ar CN

CK Ar Ar a HO HO

CN

65% yield, 88% cis O

Hydrogenation

C Cyclization

Reagents: (a) NaNH₂; (b) KMnO₄; (c) H₂/Ni or Pt; (d) B₂H₆ Or BH₃ Or LAH, then HCI

[00144] Reaction Scheme 8 provides an exemplary process for transforming the epichlorohydrin to a desired compound or intermediate of the invention via a replacement and cyclization reaction. The reaction of methyl 2-arylacetate with epichlorohydrin gives methyl 2-(hydroxymethyl)~l~arylcyclopropanecarboxylate with the desired cis isomer as the major product. The alcohol is converted into an OR₃ group such as -O-mesylate, -O- tosylate, -O-nosylate, -O-brosylate, -O-trifluoromethanesulfonate. Then OR₃ is replaced by a primary amine NH₂R₄, where R₄ is a nitrogen protection group such as a 3,4- dimethoxy-benzyl group or other known protection group. Nitrogen protecting groups are well known to those skilled in the art, see for example, “Nitrogen Protecting Groups in Organic Synthesis”, John Wiley and Sons, New York, N.Y., 1981, Chapter 7; “Nitrogen Protecting Groups in Organic Chemistry”, Plenum Press, New York, N.Y., 1973, Chapter 2; T. W. Green and P. G. M. Wuts in “Protective Groups in Organic Chemistry”, 3rd edition, John Wiley & Sons, Inc. New York, N. Y., 1999. When the nitrogen protecting group is no longer needed, it may be removed by methods well known in the art. This replacement reaction is followed by a cyclization reaction which provides the amide, which is then reduced into an amine by a reducing agent such as LAH. Finally the protection group is removed to yield the l-aryl-3- azabicyclo[3.1.0]hexane analogs. Utilizing chiral (S)-(+)-epichlorohydrin as a starting material leads to the (lR,5S)-(+)-l-aryl-3-azabicyclo[3.1.0]hexane analogs with the same reaction sequence. Similarly, the (R)-(-)-epichlorohydrin will lead to the (lS,5R)-(-)-l- aryl-3-azabicyclo[3.1.0]hexane analogs.

Reaction Scheme 8

O Cyclop ro pa nantion

Ar CO₂Me + _C|v Ar Ar

HO R₃O

CO₂Me CO₂Me

Replacement Cyclization

Reagents: (a) NaNH₂; (b) MsCI; (c) R₄NH₂; (d) LAH or SAH or BH₃; (e) HCI

[00145] Reaction Scheme 9 provides an exemplary process for transforming the diol to a desired compound or intermediate of the invention. Reduction of the diester provides the diol which is then converted into an OR₃ group such as -O-mesylate, -O- tosylate, -O-nosylate, -O-brosylate, -O-trifluoromethanesulfonate. Then OR₃ is replaced by a primary amine NH₂R₆, where R₆ is a nitrogen protection group such as a 3,4- dimethoxy-benzyl group or other protection groups known in the art (e.g., allyl amine, tert-butyl amine). When the nitrogen protecting group is no longer needed, it may be removed by methods known to those skilled in the art.

Reaction Scheme 9

X=CI or Br

Deprotection ft* Replacement Cyclization

Reagents: (a) NaOMe; (b) NaBH₄; (c)MsCI; (d) NH₃, then HCI; (e) R₆NH₂; (f) H₂/Pd or acid deprotection, then HCI

[00146] Reaction Scheme 10 provides an exemplary process for resolving the racemic l-aryl-3-aza-bicyclo[3.1.0]hexane to enantiomers. The resolution of amines through tartaric salts is generally known to those skilled in the art. For example, using O,O-Dibenzoyl-2R,3R-Tartaric Acid (made by acylating L(+)-tartaric acid with benzoyl chloride) in dichloroethane/methanol/water, racemic methamphetamine can be resolved in 80-95% yield, with an optical purity of 85-98% [Synthetic Communications 29:4315- 4319 (1999)]. Reaction Scheme 10

Racemate (1 R, 5S)-enantiomer

Racemate (1 S, 5R)-enantiomer

Reagents: (a) L-(-)-DBTA; (b) NaOH, then HCI in IPA; (c) D-(+)-DBTA

[00147] Reaction Scheme 11 provides an exemplary process for the preparation of

3-alkyl-l-aryl-3-azabicyclo[3.1.0]hexane analogs. These alkylation or reductive animation reaction reagents and conditons are generally well known to those skilled in the art.

Reaction Scheme 11

R= Me, Et, Propyl, i-propyl, cyclopropyl, i-butyl, etc.

[00148] Enantiomers of compounds within the present invention can be prepared as shown in Reaction Scheme 12 by separation through a chiral chromatography. Reaction Scheme 12

[00149] Alternatively, enantiomers of the compounds of the present invention can be prepared as shown in Reaction Scheme 13 using alkylation reaction conditions exemplified in scheme 11.

Reaction Scheme 13

[00150] Reaction Scheme 14 provides an exemplary process for preparing some N- methyl l-aryl-3-aza-bicyclo[3.1.0]hexane analogs. The common intermediate N-methyl bromomaleide is synthesized in one batch followed by Suzuki couplings with the various substituted aryl boronic acids. Cyclopropanations are then carried out to produce the imides, which are then reduced by borane to provide the desired compounds.

Reaction Scheme 14

Reagents and conditions: (a) MeNH₂, THF, 10 ⁰C, 1.5 hr; (b) NaOAc, Ac₂O₁ 60 ⁰C, 2 hr; (c) PdCI₂C dppf), CsF, dioxane, 40 ⁰C, 1-6 hr; (d) Me₃SOCI, NaH, THF, 50-65 ⁰C, 2-6 hr; (e) 1M BH₃/THF, O ⁰C; 60 ⁰C 2 hr (f) HCI, Et₂O

[00151] Reaction Scheme 15 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 15

[00152] Reaction Scheme 16 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes. Reaction scheme 16

[00153] Reaction Scheme 17 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 17

[00154] Reaction Scheme 18 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes. Utilizing chiral starting materials (+)-epichlorohydrin or (-)-epichlorohydrin will lead to the corresponding chiral analogs through the same reaction sequences. Reaction Scheme 18

[00155] Reaction Scheme 19 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 19

R= propyl , butyl, etc.

[00156] Reaction Scheme 20 provides an additional methodology for producing 1- aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 20

H

Ac₂O NaOAc, reflux

R= ferf-butyl, etc.

[00157] Reaction Scheme 21 provides an additional methodology for producing 3- and/or 4-subsitituted l-aryl-3-azabicyclo[3.1.0] hexanes. Reaction Scheme 21

(BoC)₂O DCM

R= methyl, etc. -Ar v Ar R₁ = methyl, etc. R- N H HCI

R ^• HCI

[00158] Reaction Scheme 22 provides an additional methodology for producing 3- and/or 4-subsitituted l-aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 22

(BoC)₂O DCM

1. 2.

R= Ri

[00159] Reaction Scheme 23 provides an additional methodology for producing 3- and/or 2-subsitituted 1 -aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 23

KBH₄

R = Me, etc. MeOH R₁ = Me, etc.

HCI HCI Ether Ether

[00160] Reaction Scheme 24 provides an additional methodology for producing 2- and/or 3 -substituted l-aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 24

I) TMSCI; PhMe

Et₃N; NaBH₃CN 2) R₂Li EtOH

[00161] Reaction Scheme 25 provides an additional generic methodology for producing 1 -aryl-3 -azabicyclo[3.1.0] hexanes .

Reaction Scheme 25

Ar

Cyolopropanation Ar Reduction ^Ar Cyciization / \

Ar CN + Cl HO. HO

CN

H₂N

^or Protection

[00162] Reaction Scheme 26 provides another generic methodology for producing l-aryl-3-azabicyclo[3.1.0] hexanes.

Reaction Scheme 26

⁰

Reduction Deprotection/ dealkylation

C. Synthesis of various naphthyl and phenyl 3-azabicyclo[3.1.01hexane Hydrochlorides

(1) Synthesis of lS,5R-(-Vl-(l-naphthylV3-azabicyclol3.1.01hexane Hydrochloride as Representative Procedure for (l)-(6).

[00340] To a stirring solution of ( 1 R,2S)-(2-Aminomethyl-2-( 1 – naphthyl)cyclopropyl)-methanol prepared according to Example XIVB(I) above (3.2 g, 0.014 moles) in 35 niL of dichloroethane (DCE), at room temperature under nitrogen, was added 1.2 niL (0.017 moles, 1.2 eq) of SOCl₂ slowly via syringe while keeping the temperature below 50 ⁰C. (Note: The reaction exotherms from 22 ⁰C to 45 ⁰C) The resulting mixture was stirred for 3.5 h at room temperature after which time, TLC analysis (SiO₂ plate, CH₂Cl₂/MeOH/NH₄OH (10:1:0.1)) showed no starting material remaining. The mixture was quenched with 40 mL of water and the layers were separated. The organic layer was washed with H₂O (2 x 5O mL). The aqueous layers were combined, made basic with ION NaOH to pH = 10 (pH paper) and extracted with 2 x 100 mL of CH₂Cl₂. The combined organics were dried over Na₂SO₄, filtered and concentrated to an oil. The oil was dissolved in MeOH (20 mL), treated with 15 mL of 2M HCl/Et₂O and concentrated in vacuo to a suspension. The slurry was diluted with 25 mL of Et₂O, filtered and washed with 35 mL of Et₂O. The solid product was dried overnight (-29 mmHg, 5O⁰C) to give 1 g (29%) of pure product as a white solid. ¹H NMR (400 MHz, CDCl₃) δ 1.22 (t, J=7.37 Hz, 1 H), 1.58 (dd, J=6.00, 4.73 Hz, 1 H), 2.03 – 2.10 (m, 1 H), 3.25 – 3.27 (m, 1 H), 3.42 (d, J=I 1.52 Hz, 1 H), 3.64 (d, J=I 1.62 Hz, 1 H), 3.74 – 3.85 (m, 2 H), 7.32 – 7.39 (m, 1 H), 7.40 – 7.48 (m, 2 H), 7.48 – 7.55 (m, 1 H), 7.75 (d, J=8.20 Hz, 1 H), 7.79 – 7.85 (m, 1 H), 8.04 (d, J=8.30 Hz, 1 H), ¹³C NMR (101 MHz, CDCl₃) δ 14.54, 22.43, 30.89, 48.01, 51.89, 123.92, 125.60, 126.24, 126.93, 129.04, 129.17, 133.55, 134.04, LC/MS (m/z M⁺¹) 210.0, [α]_D (c=l, MeOH), = -54.4.

(2) lR,5S-(+)-l-g-naphthyl)-3-azabicvclof3,1.01hexane Hydrochloride

[00341] Yield = 29%; ¹H NMR (400 MHz, METHANOL-^) δ 1.24 – 1.32 (m, 1

H), 1.32 – 1.37 (m, 1 H), 2.23 – 2.31 (m, 1 H), 3.47 (d, J=11.71 Hz, 1 H), 3.66 (d, J=11.71 Hz, 1 H), 3.85 (d, J=11.62 Hz, 1 H), 3.93 (dd, J=11.67, 3.95 Hz, 1 H), 7.46 (dd, J=8.25, 7.08 Hz, 1 H), 7.50 – 7.57 (m, 1 H), 7.57 – 7.65 (m, 2 H), 7.86 (d, J=8.30 Hz, 1 H), 7.89 – 7.95 (m, 1 H), 8.17 (d, J=8.49 Hz, 1 H), ¹³C NMR (101 MHz, METHANOL-^) δ 22.36, 30.65, 30.65, 48.09, 51.99, 123.78, 125.47, 125.89, 126.50, 128.65, 128.88, 133.87, 134.28, LC/MS (m/z M⁺¹ 210.0), [α]_D (c=l, MeOH), = + 55.6.

(4) lR.5S-(+)-l-(2-naphthylV3-azabicvclo[3.1.01hexane Hydrochloride

[00343] Yield = 30%; ¹H NMR (400 MHz, DMSO-J₆) δ 1.14 – 1.23 (m, 1 H), 1.44

– 1.50 (m, 1 H), 2.17 – 2.26 (m, 1 H), 3.36 – 3.43 (m, 1 H), 3.47 – 3.61 (m, 2 H), 3.75 (d, J-11.23 Hz, 1 H), 7.36 (dd, J=8.59, 1.85 Hz, 1 H), 7.42 – 7.53 (m, 2 H), 7.80 (d, J=1.56 Hz, 1 H), 7.82 – 7.90 (m, 3 H), 9.76 (br. s., 1 H), ¹³C NMR (101 MHz, DMSO-J₆) δ 16.41, 24.11, 31.36, 47.50, 49.97, 125.43, 125.76, 126.41, 127.04, 128.07, 128.15, 128.74, 132.39, 133.55, 137.62, ), LC/MS (m/z M⁺¹ 210.1 , [α]_D (c=l, MeOH), = + 66.0.

PATENT

WO 2008013856

https://www.google.com/patents/WO2008013856A2?cl=en

The compound (-^-(S^-dichlorophenylJ-S-azabicyclotS.l.Olhexane and its pharmaceutically acceptable salts have been previously described as agents for treating or preventing a disorder alleviated by inhibiting dopamine reuptake, such as depression (See, US Patent Nos. 6,569,887 and 6,716,868). However, available methods for synthesizing (-)-l-(3₃4-dichlorophenyl)-3-azabicyclo[3.1.0]hexanes and other l-aryl-3-azabicyclo[3.1.0]hexanes are presently limited.

US Patent No. 4,231,935 (Example 37) describes the synthesis of racemic (±)- l-(3,4-dichlorophenyl)-3-azabicyclo[3.1.0]hexane hydrochloride according to the following scheme.

US Patent Nos. 6,569,887 and 6,716,868 describe the preparation of (-)-l-(3,4- dichlorophenyl)-3-azabicyclo[3.1.0]hexane by resolution of racemic (±)-l-(3,4- dichlorophenyl)-3-azabicyclo[3.1.0]hexane hydrochloride using a chiral polysaccharide stationary phase. The foregoing methods provide limited tools for producing (-)-l-(3,4- dichlorophenyl)-3-azabicyclo[3.1.0] hexane and other 1-aryl— 3- azabicyclo[3.1.0]hexanes, underscoring a need for additional methods and compositions to produce the compounds.

Example VI Preparation of ClR. 5S)-l-naphthalen-2-yl-3-azabicyclof3.1.0^“|hexane hydrochloride

using Reaction Schemes 1 & 12

A. Synthesis of (IR. 2SV2-Hvdroxymethyl-2-naphthyl- cvclopropancarbonitrile

To a stirring solution of 2-naphthylacetonitrile (50.0 g, 0.299 moles) and (S)-

(+)-epichlorohydrin (36.0 g, 0389 moles) in anhydrous THF (300 mL) at -15 to -20 ⁰C under nitrogen, was added sodium bis (trimethylsilyl)amide (2M in THF, 300 mL, 0.600 moles) slowly via addition funnel while keeping the temperature between -15 ⁰C and —20 °C. After completion of the addition, the mixture was stirred for 3 hours at -15 ⁰C to -20 °C. The reaction mixture was quenched by slow addition of 2M HCl (520 mL) allowing the temperature to rise to 15 ⁰C as the neutralization proceeded. The layers were allowed to settle and the layers were separated. The aqueous layer was extracted once with ethyl acetate (30OmL). The organic portion was washed with brine (4000 mL) dried over sodium sulfate, filtered and concentrated under reduced pressure to provide an orange oil which was used without further purification. B. Synthesis of ((1S, 2R)-2-AminomethvI-2-naphthylen-2-yl cycIopropyD- methanol

To a solution of nitrile in THF (300 mL) was slowly added borane dimethylsulfide (10 M, 60 mL, 0.60 moles) via addition funnel. The reaction temperature was maintained below 60 ⁰C during the addition. After completion of the addition, the reaction was held at 60 ⁰C until the starting nitrile was completely consumed (approximately 2.5 hours). The mixture was cooled below 15 ⁰C and 2M HCl (200 mL) was slowly added maintaining a temperature below 20 ⁰C. The reaction mixture was then heated to 50⁰C for one hour. After the heating period, the reaction was cooled below 30⁰C and isopropyl acetate (200 mL) and water (250 mL) were added. The phases were separated and the organic phase was discarded. Ammonium hydroxide (75 mL) was added and the mixture cooled to 25 ⁰C with stirring. The aqueous phase was extracted with isopropyl acetate (2x 250 mL). The combined organic phases were washed with 5% dibasic sodium phosphate (200 mL) and saturated NaCl (200 mL), dried over sodium sulfate and concentrated. The viscous yellow oil was dissolved in isopropyl acetate (500 mL) and heated to 55 ⁰C with stirring. p-Toluene sulfonic acid monohydrate(54.25 g, 0.285 mole) was added over 5 minutes. A white solid formed as the acid was added. The reaction mixture was slowly cooled to room temperature, filtered and washed with isopropyl acetate. Yielded – 53.7 g white solid 45% (tosylate salt)

C. Synthesis of (IR. 5SM-naphthaIen-2-vI-3-azabicvclo[3.1.01hexane hydrochloride

To a stirring slurry of ((lS,2R)-2-aminomethyl-2-naphthylen-2-yl cyclopropyl)-methanol tosylate (53.7g, 0.134 mole) in isopropyl acetate (350 mL), at room temperature under nitrogen, was added thionyl chloride (11.8 mL, 0.161 moles) slowly via addition funnel while keeping the temperature below 35 ⁰C. The resulting mixture was stirred for 1 hour, after which time, no starting material remained. The mixture was neutralized with the slow addition of 5 N NaOH (160 mL) keeping the temperature below 30 ⁰C. The phases were separated and the aqueous phase was extracted with isopropyl acetate (200 mL). The combined organic extracts were washed with saturated sodium chloride (150 mL), dried over sodium sulfate, filtered and concentrated to 300 mL. The hydrochloride was made directly from this solution by slowly adding HCl in 2-propanol (5-6N, 26 mL). The mixture was stirred for 15 minutes and filtered and washed with isopropyl acetate. The wet cake was slurried in 2-propanol (400 mL) and heated to reflux with stirring under nitrogen for 2 hours. The resulting slurry was allowed to cool and stir at room temperature overnight. The resulting slurry was filtered and washed with 2-propanol. The solid was dried in a vacuum oven at 40⁰C. Yield – 21.1 g, 64.2% ¹H NMR (400 MHz, DMSCW₆) d ppm 1.23 (t) 1.40 (t) 2.21 – 2.28 (m) 3.40 – 3.47 (m) 3.50 – 3.66 (m) 3.74 – 3.82 (m) 7.39 (dd) 7.44 – 7.55 (m) 7.82 (s) 7.84 – 7.92 (m) 9.33 (br. s.) 9.69 (br. s.). LC/MS (m/z M⁺¹ 210)

PATENT

WO 2013019271

https://google.com/patents/WO2013019271A1?cl=en

Example I

Preparation of (lR,5S)-(+)-l-(naphthalen-2-yl)-3-azabicyclo[3.1.0]hexane

[00108] (lR,5S)-(+)-l-(naphthalen-2-yl)-3-azabicyclo[3.1.0]hexane may be prepared as follows:

Step 1: Synthesis of [(lS.2R)-2-(aminomethyl)-2-(2-naphthyl^‘)cvclopropyl]methan-l-oK p- toluenesulfonic acid salt [00109] 500g (2.99 mol, 1.0 eq) of 2-naphthylacetonitrile was charged to a 12 L 3- neck round bottom flask equipped with overhead stirrer, addition funnel, thermocouple, nitrogen inlet, cooling bath and drying tube. 3.0 L of tetrahydrofuran was added and stirred at room temperature to dissolve all solids. 360 g (3.89 mol, 1.30 eq) (S)-(+)-epichlorohydrin was added and then the solution was cooled to an internal temperature of – 25 °C. 3.0 L of a 2 molar solution of sodium bis(trimethylsilyl)amide in tetrahydrofuran (6.00 mol, 2.0 eq) was added to the reaction mixture via addition funnel at a rate such that the internal temperature of the reaction mixture is maintained at less than -15 °C. After completion of the addition, the mixture was stirred at between -20 °C and -14 °C for 2 hours 15 minutes. Borane- dimethylsulfide complex (750 mL of a 10.0 molar solution, 7.5 mol, 2.5 eq) was then slowly added to the reaction mixture at a rate such that the internal temperature was maintained at less than -5 °C. Upon completion of the borane-dimethylsulfide addition the reaction mixture was heated to an internal temperature of 60 °C and stirred overnight at this temperature. Additional borane-dimethylsulfide complex (75 mL, 0.75 mol, 0.25 eq) was then added and the reaction mixture stirred at 60 °C for 1 hour 45 minutes. The reaction mixture was cooled to room temperature and then quenched by slow addition into pre-cooled (3 °C) 2 molar aqueous hydrochloric acid (5.76 L, 11.5 mol, 3.8 eq) at a rate such that the temperature of the quench solution was maintained at less than 22 °C. The two phase mixture was then heated at an internal temperature of 50 °C for 1 hour followed by cooling to RT. Isopropyl acetate (2.0 L) and water (2.5 L) were added, the mixture agitated, and then the layers were allowed to settle. The upper organic layer was discarded. Aqueous ammonia (750 mL) was added to the aqueous layer which was then extracted with isopropylacetate (2.5 L). The aqueous layer was extracted with isopropylacetate (2.5 L) a second time. The organic extracts were combined and then sequentially washed with a 5% solution of sodium dibasic phosphate in water (2.0 L) followed by saturated brine (2.0 L). The organic layer was then concentrated to a total volume of 5.0 L and then heated to 50 °C. para-Toluene sulfonic acid monohydrate (541 g, 2.84 mol) was then added in portions. During the addition white solids precipitated and a mild exotherm was observed. Upon completion of the addition the mixture was allowed to cool to RT and the solids collected by filtration. The filtercake was washed twice with isopropylacetate, 1.0 L each wash. The filtercake was then dried to a constant weight to give 664.3 g (55% yield) of the desired product as a white solid. Step 2: Synthesis of (5S.lRVl-(2-naphthylV3-azabicvclor3.1.01hexane HC1 salt

[00110] The amine-tosylate salt from step 1 (2037.9 g, 5.10 mol) was suspended in isopropylacetate ( 13.2 L) to give a white slurry in a 50 L 3 -neck RB equipped with an overhead stirrer, thermocouple, addition funnel, nitrogen inlet and drying tube.

Thionylchloride (445 mL, 6.12 mol, 1.20 eq) was then added via addition funnel over one hour 5 minutes. The maximum internal temperature was 24 °C. After stirring for 4 hours 15 minutes 5 molar aqueous sodium hydroxide (6.1 L, 30.5 mol, 5.98 eq) was added via addition funnel at a rate such that the maximum internal temperature was 30 °C. The mixture was then stirred for one hour 15 minutes after which the layers were allowed to settle and the layers were separated. The organic layer was washed with 1 molar aqueous sodium hydroxide (2.1 L). The aqueous layers were then combined and back extracted with isopropyl acetate (7.6 L). The organic layers were combined and washed with saturated aqueous brine (4.1 L). The organic layer was then dried over magnesium sulfate, filtered to remove solids, and then concentrated to a total volume of 4.2 L in vacuo. Hydrogen chloride in isopropyl alcohol (5.7 N, 0.90 L, 5.13 mol, 1 eq) was then added over 50 minutes using an external water/ice bath to keep the internal temperature less than 30 °C. After stirring for 45 minutes the solids were collected by filtration and the filtercake washed two times with isopropyl acetate, 2.3 L each wash. The filtercake was then partially dried and then taken forward to step 3 as a wetcake.

Step 3: Crude (5S.lRVl-(2-naphthyl -3-azabicvclof3.1.01hexane HC1 salt hot slurry in isopropyl alcohol

[00111] The wetcakes from two separate runs of step 2 (total of 4646.6 g starting amine tosylate salt) were combined and suspended in isopropyl alcohol (34.6 L) in a 50 L 3- neck round bottom flask equipped with overhead stirrer, heating mantel, thermocouple, reflux condenser, nitrogen inlet, and drying tube. The slurry was then heated to reflux, stirred for three hours at reflux, and then allowed to cool to room temperature. The solids were collected by filtration and the filtercake washed twice with isopropyl alcohol, 6.9 L each wash. The filtercake was then dried to a constant weight to give 2009.2 g of (5S,1R)-1- (2-naphthyl)-3-azabicyclo[3.1.0]hexane HCl salt (70 % yield from 4646.6 g of amine tosylate salt).

Step 4: Recrvstallization of (5S.lRVl-(2-naDhthvn-3-a2abicvclor3.1.01hexane HCl salt from ethanol to upgrade the enantiomeric excess

[00112] The (5S,lR)-l-(2-naphthyl)-3-azabicyclo[3.1.0]hexane HCl salt from step 3 (2009.2 g, 8.18 mol) was charged to a 50 L 3-neck round bottom flask equipped with an overhead stirrer, heating mantel, reflux condenser, nitrogen inlet, thermocouple, and drying tube. Ethanol (21.5 L of special industrial) was then added and the mixture heated to reflux to dissolve all solids. After dissolution of solids heating was discontinued and the mixture was allowed to cool to room temperature during which time solids reformed. The solids were then collected by filtration and the filtercake washed with ethanol (4.3 L). The filtercake was then dried to a constant weight to give 1434.6 g (71 % yield ) of recrystallized (5S,lR)-l-(2-naphthyl)-3-azabicyclo[3.1.0]hexane HCl salt. Chiral HPLC assay showed an enantiomeric excess of > 99.5 %.

Step 5: Rework to improve color profile

[00113] (5S,lR)-l-(2-naphthyl)-3-azabicyclo[3.1.0]hexane HCl (1405.6 g, 5.72 mol) was charged to a 22 L 3-neck round bottom flask equipped with overhead stirrer, heating mantel, thermocouple, nitrogen inlet and drying tube. Water (14.0 L) was added and the mixture heated to 34 °C to dissolve all solids. The solution was then transferred to a large separatory funnel and teti^ydrofuran (2.8 L) followed by isopropyl acetate (2.8 L) was added. The two phase mixture was agitated and the layers were then allowed to settle. The upper organic layer was discarded. Aqueous ammonia (1.14 L) was then added and the aqueous layer extracted with isopropylacetate (14.0 L). The organic layer was dried over magnesium sulfate, filtered, and concentrated in vacuo to give an off-white solid. The solid was dissolved in isopropyl alcohol (14.0L) and transferred to a 22 L 3-neck round bottom flask equipped with overhead stirrer, thermocouple, addition funnel, nitrogen inlet and drying tube. Hydrogen chloride in isopropyl alcohol (5.7 N, 175 mL, 1.0 mol) was then added over 10 minutes. Near the end of this addition the formation of solids was evident. The slurry was stirred for 30 minutes then additional hydrogen chloride in isopropanol (840 mL, 4.45 mol) was added over 65 minutes keeping the internal temperature less than 25 °C. The solids were collected by filtration and the filtercake washed twice with isopropyl alcohol, 2.8 L each wash. The filtercake was then dried to a constant weight to give 1277.1 g (91% yield) of the product as an off-white solid.

PATENTS

WO-2016205762

(lR,5S)-l-(naphthalen-2-yl)-3-azabicyclo[3.1.0]hexane, also known as (+)-l- (naphthalen-2-yl)-3-azabicyclo[3.1.0]hexane, is a compound useful as an unbalanced triple reuptake inhibitor (TRI), most potent towards norepinephrine reuptake (NE), one-sixth as potent towards dopamine reuptake (DA), and one-fourteenth as much towards serotonin reuptake (5- HT). This compound and its utility are disclosed in more detail in U.S. Patent Publication No. 2007/0082940, the contents of which are hereby incorporated by reference in their entirety

References

External links

• Centanafadine – AdisInsight

Centanafadine

Legal status
Legal status	Investigational New Drug
Identifiers
IUPAC name[show]
CAS Number	924012-43-1
PubChem (CID)	16095349
ChemSpider	17253639
Chemical and physical data
Formula	C15H15N
Molar mass	209.28 g/mol
3D model (Jmol)	Interactive image
SMILES C1=C(C=CC2=CC=CC=C12)[C@@]34C[C@@H]3CNC4

///////CENTANAFADINE, PHASE 2, UNII-D2A6T4UH9C, EB-1020, D2A6T4UH9C, 924012-43-1, CTN SR, EB-1020, EB-1020 SR,

C1C2C1(CNC2)C3=CC4=CC=CC=C4C=C3

Balsalazide

(3E)-3-[[4-(2-carboxyethylcarbamoyl)phenyl]hydrazinylidene]-6-oxocyclohexa-1,4-diene-1-carboxylic acid

 DISODIUMDIHYDRATE

Balsalazide is an anti-inflammatory drug used in the treatment of inflammatory bowel disease. It is sold under the brand names Giazo, Colazal in the US and Colazide in the UK. It is also sold in generic form in the US by several generic manufacturers.

It is usually administered as the disodium salt. Balsalazide releases mesalazine, also known as 5-aminosalicylic acid, or 5-ASA,^[1] in the large intestine. Its advantage over that drug in the treatment of ulcerative colitis is believed to be the delivery of the active agent past the small intestine to the large intestine, the active site of ulcerative colitis.

Balsalazide is an anti-inflammatory drug used in the treatment of Inflammatory Bowel Disease. It is sold under the name “Colazal” in the US and “Colazide” in the UK. The chemical name is (E)-5-[[-4-(2-carboxyethyl) aminocarbonyl] phenyl]azo] –2-hydroxybenzoic acid. It is usually administered as the disodium salt. Balsalazide releases mesalazine, also known as 5-aminosalicylic acid, or 5-ASA, in the large intestine. Its advantage over that drug in the treatment of Ulcerative colitis is believed to be the delivery of the active agent past the small intestine to the large intestine, the active site of ulcerative colitis.

Balsalazide disodium and its complete synthesis was first disclosed by Chan[18] in 1983, assigned to Biorex Laboratories Limited, England, claiming product ‘Balsalazide’ and process of its preparation. The synthesis involves converting 4-nitrobenzoyl chloride (6) to 4- nitrobenzoyl-β-alanine (7), hydrogenating with Pd/C (5%) in ethanol and isolating by adding diethyl ether to produce 4-aminobenzoyl-β-alanine (8). Thereafter, 4-aminobenzoyl-β-alanine (8) was treated with hydrochloric acid and sodium nitrite to generate N-(4-diazoniumbenzoyl)- β-alanine hydrochloride salt (9) which was reacted at low temperature with disodium salicylate to furnish Balsalazide disodium insitu which was added to dilute hydrochloric acid at low temperature to produce Balsalazide (1) (Scheme-1.1). Thus obtained Balsalazide was recrystallized with hot ethanol and converted to pharmaceutically acceptable salt (disodium salt).

Optimization of this diazonium salt based process was performed by Huijun et al[19] and reported the preparation of the title compound in 64.6% overall yield. Zhenhau et al[20] have synthesized 1 from 4-nitrobenzoic acid (12) via chlorination, condensation, hydrogenation, diazotization, coupling and salt formation with overall yield 73%. Li et al[21] have given product in 73.9% total yield starting from 4-nitrobenzoyl chloride (6), where as Yuzhu et al[22] confirmed chemical structure of Balsalazide disodium by elemental analysis, UV, IR, 1H-NMR and ESI-MS etc. Shaojie et al[23] have also followed same process for its preparation. Yujie et al[24] synthesized 1 in this way; preparation of 4-nitrobenzoyl-β-alanine (7) under microwave irradiation of 420 W at 52oC for 10sec., reduction in ethyl acetate in the presence of Pd/C catalyst then diazotization, coupling and salt formation. Eckardt et al[25] have developed a process for the preparation of Balsalazide which comprises, conversion of 4-aminobenzoyl-β-alanine (8) to 4-ammoniumbenzoyl-β-alanine sulfonate salt using a sulfonic acid in water. This was treated with aq. sodium nitrite solution at low temperature to generate 4-diazoniumbenzoyl-β-alanine sulfonate salt (11) which was quenched with aq. disodium salicylate to furnish Balsalazide disodium solution. This was further acidified to allow isolation of 1 and then conversion to disodium salt (Scheme-1.2) in 76% yield.

http://shodhganga.inflibnet.ac.in/bitstream/10603/101297/10/10_chapter%201.pdf

IR (KBr, cm-1 ): 3371 and 3039 (OH and NH), 1705 and 1699 (C=O), 1634 (C=O amide), 1590 and 1538 (C=C aromatic), 1464 and 1404 (aliphatic C-H), 1229 (C-N), 1073 (C-O), 773 and 738 (Ar-H out of plane bend). 1H NMR (DMSO-d6, 300 MHz, δ ppm): 2.54 (t, 2H), 3.50 (m, 2H), 6.95 (d, J = 8.8 Hz, 1H), 7.87 (d, J = 8.5 Hz, 2H), 8.02 (d, J = 8.5 Hz, 2H), 7.95 (dd, J = 8.8 Hz and 2.5 Hz, 1H), 8.34 (d, J = 2.5 Hz, 1H), 8.68 (t, J = 5.5 Hz, 1H), 12.12 (brs, 1H). MS m/z (ESI): 356 [(M-H)- ], Calculated; m/z 357.

Synthesis

1. Starting material is 4-aminohippuric acid, obtained by coupling para-aminobenzoic acid and glycine.
2. That product is then treated with nitrous acid to give the diazonium salt.
3. Reaction of this species with salicylic acid proceeds at the position para to the phenol to give balsalazide.

Sodium balsalazide (Balsalazide sodium)

Brief background information

Application

Classes substance

Synthesis Way

Synthesis of a)

Trade names

Formulations

• capsules in 750 mg (as disodium salt)

PATENT

https://www.google.com/patents/US7271253

Balsalazide disodium (1) represents an effective gastrointestinal anti-inflammatory compound useful as a medicament for the treatment of diseases such as ulcerative colitis. It is delivered intact to the colon where it is cleaved by bacterial azoreduction thereby generating 5-aminosalicylic acid as the medicinally active component.

To date, relatively few patents or literature articles have dealt with the preparation of Balsalazide or the disodium salt. For instance, U.S. Pat. No. 4,412,992 (Biorex, 1983) is the first patent that we uncovered that claims the compound Balsalazide and a strategy of how to prepare it which strategy is depicted in Scheme 1.

Optimization of this diazonium-based process is detailed in Shan et al., Zhongguo Yaowu Huaxue Zazhi, 11, 110 (2001) and Shi et al., Zhongguo Yiyao Gongye Zazhi, 34, 537 (2003).

Problems arise with the above strategy and the optimization process.

It is well-documented in the literature, for instance in Thermochimica Acta, 225, 201-211 (1993), that diazonium salts can be involved in serious accidents in their use. A possible cause of some of the diazonium salt related accidents is that, for one reason or another, an intermediate material appeared in crystalline form in the vessel of the reaction. As a result, a potentially severe drawback of the above processes occurs. Since the intermediate hydrochloride salt of 4-aminobenzoyl-β-alanine has poor solubility in water, it may pose a safety-risk in the subsequent diazotation reaction.

Also, it is well-known that certain diazonium salts possess high mechanical and heat sensitivity and that their decomposition goes through the liberation of non-condensable nitrogen gas which results in the possibility of runaway reactions and explosions. Obviously this safety consideration becomes more pertinent upon further scale-up.

Therefore, for commercial production of Balsalazide disodium, there was a need to develop a scalable and intrinsically better process

Example 1 Batch Process

N-(4-Aminobenzoyl)-β-alanine (100 g) was suspended in water (1300 mL) and methanesulfonic acid (115.4 g) was added to this mixture. The mixture was cooled to 10° C. and a solution of sodium nitrite (34.46 g) in water (200 mL) was added at a rate such that the temperature stayed below 12° C. The mixture was stirred for 30 min and added to an ice-cold solution of salicylic acid (69.65 g), sodium hydroxide (40.35 g) and sodium carbonate (106.9 g) in 1 L water at 7-12° C. After 3 hours at 10° C., the mixture was heated to 60-65° C. and acidified to pH 4.0-4.5 by the addition of hydrochloric acid. After a further 3 hours at 60-65° C., the mixture was cooled to ambient temperature, filtered, washed with water and dried in vacuo to yield Balsalazide. Yield ca. 90%. Balsalazide was transformed into its disodium salt in ca. 85% yield by treatment with aqueous NaOH solution followed by crystallization from n-propanol/methanol.

¹H-NMR (400 MHz; D₂O): δ=8.04 ppm (s); 7.67 ppm (d; J=8.2 Hz); 7.62 ppm (d, J=9.2 Hz); 7.53 ppm (d; J=8.2 Hz); 6.84 ppm (d; J=8.9 Hz); 3.57 ppm (t, J=7.1 Hz); 2.53 ppm (t; J=7.2 Hz).

Example 2 Continuous Process

For the continuous operation, a conventional dual-head metering pump (Ratiomatic by FMI) was used to deliver the mesylate solution and the aqueous sodium nitrite solution. The schematic diagram shown in FIG. 4 represents a set-up used for the continuous process. The first pump-head was set at 13.9 g/min whereas the second was set at 2.1 g/min. These flow rates offered a residence time of 9.4 min. The yield of the coupled intermediate from this residence time was 93%. The working solutions were prepared as follow:

The mesylate solution was prepared by the addition into a 2 L 3-necked round bottom flask, of N-(4-aminobenzoyl) β-alanine (120 g) followed by of DI water (1560 g) and methanesulfonic acid (177.5 g) (Batch appearance: clear solution). The first pump-head was primed with this solution and the flow rate was adjusted to 13.9 g/min.

The sodium nitrite solution was prepared by dissolving of sodium nitrite (41.8 g) in of DI water (240 g) (Batch appearance: clear solution). The second pump-head was primed with this solution and the flow rate adjusted to 2.1 g/min.

The quenching solution (sodium salicylate) was made by adding salicylic acid (139.3 g) to DI water (900 g) followed by of sodium carbonate (106.9 g) and 50% aqueous sodium hydroxide (80 g).

The diazotation reaction was performed in a 500 ml jacketed flow reactor with a bottom drain valve. The drain valve was set at 16 g/min. For reactor start-up, the flow reactor was charged with 150 mL of DI water as a working volume and cooled to the reactions initial temperature of 0-5° C. Concomitantly, the additions of the mesylate and sodium nitrite solutions were started and the bottom valve of the flow reactor was opened. During the diazotization, the flow rate of both solutions remained fixed and the temperature was kept below 12° C. and at the end of additions the pumps were stopped while the remaining contents in the flow reactor were drained into the quenching salicylic acid solution. Analysis of the contents in the quenching reactor indicated no signs of uncoupled starting material (diazonium compound). The reactor contents were heated to 60-65° C. for 2-3 hrs before adjusting the pH to precipitate the coupling product. This provided 191.5 g of product.

References

References

Balsalazide

Clinical data
Trade names	Colazal, Giazo
AHFS/Drugs.com	Monograph
MedlinePlus	a699052
Pregnancy category	US: B (No risk in non-human studies)
ATC code	A07EC04 (WHO)
Legal status
Legal status	UK: POM (Prescription only)
Pharmacokinetic data
Bioavailability	<1%
Protein binding	≥99%
Biological half-life	12hr
Identifiers
IUPAC name[show]
CAS Number	80573-04-2
PubChem (CID)	5362070
DrugBank	DB01014
ChemSpider	10662422
UNII	P80AL8J7ZP
ChEBI	CHEBI:267413
ChEMBL	CHEMBL1201346
ECHA InfoCard	100.117.186
Chemical and physical data
Formula	C17H15N3O6
Molar mass	357.318 g/mol
3D model (Jmol)	Interactive image

CLICK ON IMAGE

//////

O=C(O)c1cc(ccc1O)/N=N/c2ccc(cc2)C(=O)NCCC(O)=O

Calcifediol

カルシフェジオール

Calcifediol (INN), also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D (abbreviated 25(OH)D),^[1] is a prehormone that is produced in the liver by hydroxylation of vitamin D₃ (cholecalciferol) by the enzyme cholecalciferol 25-hydroxylase which was isolated by Michael F. Holick. Physicians worldwide measure this metabolite to determine a patient’s vitamin D status.^[2] At a typical daily intake of vitamin D3, its full conversion to calcifediol takes approximately 7 days.^[3]

Calcifediol is then converted in the kidneys (by the enzyme 25(OH)D-1α-hydroxylase) into calcitriol (1,25-(OH)₂D₃), a secosteroid hormone that is the active form of vitamin D. It can also be converted into 24-hydroxycalcidiol in the kidneys via 24-hydroxylation.^[4][5]

Blood test

In medicine, a 25-hydroxy vitamin D (calcifediol) blood test is used to determine how much vitamin D is in the body.^[6] The blood concentration of calcifediol is considered the best indicator of vitamin D status.^[7]

This test can be used to diagnose vitamin D deficiency, and it is indicated in patients with high risk for vitamin D deficiency and when the results of the test would be used as supporting evidence for beginning aggressive therapies.^[8] Patients with osteoporosis, chronic kidney disease, malabsorption, obesity, and some other infections may be high risk and thus have greater indication for this test.^[8] Although vitamin D deficiency is common in some populations including those living at higher latitudes or with limited sun exposure, the 25(OH)D test is not indicated for entire populations.^[8] Physicians may advise low risk patients to take over-the-counter vitamin D in place of having screening.^[8]

It is the most sensitive measure,^[9] though experts have called for improved standardization and reproducibility across different laboratories.^[7] According to MedlinePlus, the normal range of calcifediol is 30.0 to 74.0 ng/mL.^[6] The normal range varies widely depending on several factors, including age and geographic location. A broad reference range of 20–150 nmol/L (8-60 ng/ml) has also been suggested,^[10] while other studies have defined levels below 80 nmol/L (32 ng/ml) as indicative of vitamin D deficiency.^[11]

US labs generally report 25(OH)D levels as ng/mL. Other countries often use nmol/L. Multiply ng/mL by 2.5 to convert to nmol/L.

Clinical significance

Increasing calcifediol levels are associated with increasing fractional absorption of calcium from the gut up to levels of 80 nmol/L (32 ng/mL).^{[citation needed]}Urinary calcium excretion balances intestinal calcium absorption and does not increase with calcifediol levels up to ~400 nmol/L (160 ng/mL).^[12]

A study by Cedric F. Garland and Frank C. Garland of the University of California, San Diego analyzed the blood from 25,000 volunteers from Washington County, Maryland, finding that those with the highest levels of calcifediol had a risk of colon cancer that was one-fifth of typical rates.^[13] However, randomized controlled trials failed to find a significant correlation between vitamin D supplementation and the risk of colon cancer.^[14]

A 2012 registry study of the population of Copenhagen, Denmark, found a correlation between both low and high serum levels and increased mortality, with a level of 50–60 nmol/L being associated with the lowest mortality. The study did not show causation.^[15][16]

Nmr

http://onlinelibrary.wiley.com/doi/10.1002/cctc.201402795/epdf?r3_referer=wol&tracking_action=preview_click&show_checkout=1&purchase_referrer=onlinelibrary.wiley.com&purchase_site_license=LICENSE_DENIED

Regioselective Hydroxylation in the Production of 25-Hydroxyvitamin D by Coprinopsis cinerea Peroxygenase
ChemCatChem (2015), 7, (2), 283-290

1H NMR 500 MHz, CDCl₃: δ= 0.55 (3 H, s, 18-H), 0.94 (1H, d, J= 6.5 Hz, 21-H), 1.06 (1H, m, 22-H), 1.22 (3 H, s, 26-H), 1.22 (3 H, s, 27-H), 1.23 (1H, m, 23-H), 1.27 (1H, m, 16-H), 1.28 (1H, m, 14-H), 1.29 (1H, m, 12-H), 1.37 (1H, m, 22-H), 1.38 (1H, m, 20-H), 1.39 (1H, m, 24-H), 1.42 (1H, m, 23-H), 1.44 (1H, m, 24-H), 1.47 (2 H, m, 11-H), 1.53 (1H, m, 15-H), 1.66 (1H, m, 15-H), 1.67 (1H, m, 2-H), 1.67 (1H, m, 9-H), 1.87 (1H, m, 16-H), 1.92 (1H, m, 2-H), 1.98 (1H, m, 17-H), 2.06 (1H, m, 12-H), 2.17 (1H, m, 1-H), 2.40 (1H, m, 1-H), 2.57 (1H, dd, J= 3.7, 13.1Hz, 4-H), 2.82 (1H, m, 9-H), 3.95 (1H, bm, 3-H), 4.82 (1H, m, 19-H), 5.05 (1H, m, 19-H), 6.03 (1H, d, J=11.2 Hz, 7-H), 6.23 ppm (1H, d, J= 11.2 Hz, 6-H).

13 C NMR 500 MHz, CDCl₃: δ = 12.2 (C-18), 19.0 (C-21), 21.0 (C-23), 22.4 (C-11), 23.7 (C-15), 27.8 (C-16), 29.2 (C-9), 29.4 (C-27), 29.5 (C-26), 32.1 (C-1), 35.3 (C-2), 36.3 (C-20), 36.6 (C-22), 40.7 (C-12), 44.6 (C-24), 46.0 (C-13), 46.1 (C-4), 56.5 (C-17), 56.7 (C-14), 69.4 (C-3), 71.3 (C-25), 112.6 (C-19), 117.7 (C-7), 122.2 (C-6), 135.2 (C-5), 142.4 (C-8), 145.3 ppm (C-10).

PAPER

From Organic & Biomolecular Chemistry, 10(27), 5205-5211; 2012

http://pubs.rsc.org/en/content/articlelanding/2012/ob/c2ob25511a#!divAbstract

An efficient, two-stage, continuous-flow synthesis of 1α,25-(OH)₂-vitamin D₃ (activated vitamin D₃) and its analogues was achieved. The developed method afforded the desired products in satisfactory yields using a high-intensity and economical light source, i.e., a high-pressure mercury lamp. In addition, our method required neither intermediate purification nor high-dilution conditions.

1H NMR(400 MHz, CDCl₃): δ 8.13 (m, 2H), 7.68 (m, 2H), 6.64 (d, J = 8.3 Hz, 1H), 6.25 (d, J = 8.3 Hz, 1H), 5.19 (m, 2H), 3.93 (dd, J = 12.7, 8.2, 1H), 3.88 (dd, J = 14.6, 4.9 Hz, 1H), 3.58 (m, 1H), 1.02 (s, 3H), 1.02 (d, J = 6.8 Hz, 3H), 0.90 (d, J = 6.8 Hz, 3H), 0.86 (s, 9H), 0.80-0.84 (m, 9H), 0.09 (s, 3H), 0.00 (s, 3H)

13C NMR  (100 MHz, CDCl₃): δ 161.8, 159.6, 138.5, 135.3, 132.6, 132.5, 132.1, 130.6, 130.2, 128.7, 127.0, 126.5, 77.2, 68.5, 67.4, 67.1, 56.5, 50.6, 49.0, 44.2, 42.7, 40.4, 39.9, 39.3, 35.6, 34.7, 33.0, 30.5, 28.2, 25.9, 24.5, 21.9, 20.8, 19.9, 19.7, 18.5, 18.0, 17.4, 13.3, -4.4, -4.9

Interactive pathway map

Click on genes, proteins and metabolites below to link to respective articles. ^{[§ 1]}

References

Calcifediol

Names
IUPAC names (6R)-6-[(1R,3aR,4E,7aR)-4-[(2Z)-2-[(5S)-5- Hydroxy-2-methylidene-cyclohexylidene] ethylidene]-7a-methyl-2,3,3a,5,6,7-hexahydro- 1H-inden-1-yl]-2-methyl-heptan-2-ol
Other names 25-Hydroxyvitamin D3 25-Hydroxycholecalciferol Calcidiol
Identifiers
CAS Number	19356-17-3
3D model (Jmol)	Interactive image
ChEBI	CHEBI:17933
ChEMBL	ChEMBL1222
ChemSpider	4446820
DrugBank	DB00146
ECHA InfoCard	100.039.067
IUPHAR/BPS	6921
MeSH	Calcifediol
PubChem	5283731
UNII	T0WXW8F54E
InChI[show]
SMILES[show]
Properties
Chemical formula	C27H44O2
Molar mass	400.64 g/mol
Pharmacology
ATC code	A11CC06 (WHO)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

/////////Calcifediol, カルシフェジオール

CC(CCCC(C)(C)O)C1CCC2C1(CCCC2=CC=C3CC(CCC3=C)O)C

CAS 186348-69-6

1,4-Benzodioxin-5-carboxamide, 8-amino-7-chloro-N-(1,4-diazabicyclo[2.2.2]oct-2-ylmethyl)-2,3-dihydro-, (-)-

MW, 352.82, C₁₆ H₂₁ Cl N₄ O₃

US5663173 (A)  –  N-[(1,4-diazabicyclo[2.2.2] oct-2-yl)methyl] benzamide derivatives, their preparations and their application in therapeutics

SL65.0102-10

(-)-1,4-benzodioxin-5-carboxamide-8-amino-7-chloro-N-(1,4-diazabicyclo[2.2.2]oct-2- ylmethyl)-2,3-dihydro-, hydrochloride

CAS 186348-31-2, C₁₆ H₂₁ Cl N₄ O₃ . 2 Cl H

Melting point: 220 ° C. (decomposition). EP0748807
[α] = -16.9 ° (c = 1, H ₂ O).

[α]D = -17.9 (C = 0.75, DMSO, t = 23°C) at 589 nm. DOI: 10.1021/acs.oprd.6b00262

5-HT₃ and 5-HT₄ inhibitor that was potentially useful for the treatment of neurological disorders.

Innovators-sanofi

Hoechst Marion Roussel (Sanofi) my organisation 1993-1997 Process development at Mulund, Mumbai, India.

CENTRE IS DR RALPH STAPEL, HEAD PROCESS DEVELOPMENT, SANOFI

The 5-HT4 receptor is a G-protein coupled receptor (GPCR) which belongs to the serotonin receptor family. The role of the 5-HT₄ receptor in the modulation of many diseases is well described in the literature.(1)

During the last decades, an impressive body of evidence suggested that selective stimulation of neuronal 5-HT₄ receptor subtypes could be beneficial in the symptomatic treatment of memory disorders, including many antidepressants, antipsychotics, anorectics, antiemetics, gastroprokinetic agents, antimigraine agents, hallucinogens, and antactogens.(2)

Within effort to discover treatments of memory dysfunction, SL65.0102-10, a selective 5-HT₄ partial agonist (K_i 6.6 μM), was discovered as promising agent for the treatment of cognition impairment. Serotonin receptors are the target of a variety of pharmaceutical drugs; SL65.0102-10  emerged as a promising 5-HT₃ and 5-HT₄ inhibitor that was potentially useful for the treatment of neurological disorders.(3)

Samir Jegham

SYNTHESIS

SL65.0102-10

CONTD…………..

Synthesis

PATENT

(EP0748807) Derivatives of N- (1,4-diazabicyclo (2.2.2) -oct-2-yl) methyl benzamide, their preparation and their therapeutic use

https://patentscope.wipo.int/search/en/detail.jsf?docId=EP12807129&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

Example 5 (Compound No. 9)

Ethyl (-) – 8-Amino-7-chloro- N – [(1,4-diazabicyclo [2.2.2] oct-2-yl) methyl] -2,3-dihydro-1,4 Benzodioxin-5-carboxamide.

5.1. (+) – (2,2-dimethyl-1,3-dioxolan-4-yl) methyl methanesulfonate.

The procedure described in Example 4.1, but from (+) – 2,2-dimethyl-1,3-dioxolane-4-methanol.

5.2. (-) – 2 – [(2,2-Dimethyl-1,3-dioxolan-4-yl) methyl] -1 H -isoindole-1,3 (2 H ) -dione.

The procedure described in Example 4.2, from methane sulfonate (+) – (2,2-dimethyl-1,3-dioxolan-4-yl) methyl.
Melting point: 81.2-81.3 ° C.
[α]= -34.9 ° (c = 1, CH ₂ Cl ₂ ).

5.3. (-) – 2- (2,3-dihydroxypropyl) -1 H -isoindole-1,3 (2 H ) -dione.

The procedure described in Example 4.3, from (-) – 2 – [(2,2-dimethyl-1,3-dioxolan-4-yl) methyl] -1 H -isoindole-1, 3 (2 H ) -dione.
Melting point: 122.8-122.9 ° C.
[α]= -48.8 ° (c = 1, CH ₃ OH).

5.4. (-) – 2 – [(2-Phenyl-1,3-dioxolan-4-yl) methyl] -1 H -isoindole-1,3 (2 H ) -dione.

The procedure described in Example 4.4, from (-) – 2- (2,3-dihydroxypropyl) -1 H -isoindole-1,3 (2 H ) -dione.
Melting point: 84 ° C.
[α]= -59 ° (c = 1, CH ₂ Cl ₂ ).

5.5. Benzoate (-) – 2-bromomethyl-1- (1,3-dihydro-1,3-dioxo-2 H -isoindol-2-yl) ethyl.

The procedure described in Example 4.5, from (-) – 2 – [(2-phenyl-1,3-dioxolan-4-yl) methyl] -1 H -isoindole-1,3 ( 2 H ) -dione.
Melting point: 118.4-118.6 ° C.
[α]= -58.2 ° (c = 1, CH ₂ Cl ₂ ).

5.6. (+) – 2- (oxiranylmethyl) -1 H -isoindole-1,3 (2 H ) -dione. Fusion point :

The procedure described in Example 4.6, from benzoate (-) – 2-bromomethyl-1- (1,3-dihydro-1,3-dioxo-2 H -isoindol-2-yl) ethyl.
Melting point: 100.4-100.5 ° C.
[α]= + 45.5 ° (c = 1, CHCl ₃ ).

5.7. Dihydrochloride (-) – 8-Amino-7-chloro- N – [(1,4-diazabicyclo [2.2.2] oct-2-yl) methyl] -2,3-dihydro-1,4-benzodioxin-5 -carboxamide.

The procedure described in Example 4.7, from (+) – 2- (oxiranylmethyl) -1 H -isoindole-1,3 (2 H ) -dione.
Melting point: 220 ° C. (decomposition).
[α] = -16.9 ° (c = 1, H ₂ O).

Paper

The process development and improvements for route selection, adapted to large scale for the pilot-scale preparation of SL65.0102-10, an N-diazabicyclo[2.2.2]-octylmethyl benzamide, a 5-HT₃and 5-HT₄ receptor active ligand for the treatment of neurological disorders such as cognition impairment, are described in this article. Notable steps and enhancements are compared to the original route, including the improvement of a chiral epoxide synthesis by shortening the number of chemical steps, the deprotection of a quaternary ammonium salt, and the redesign of the final amidification coupling to avoid chromatography.

Philippe Lienard

Pilot Scale Process Development of SL65.0102-10, an N-Diazabicyclo[2.2.2]-octylmethyl Benzamide

Philippe Lienard^* , Philippe Gradoz, Hélène Greciet, Samir Jegham, and Didier Legroux

Sanofi-Aventis, Recherche & Développement, 13 Quai Jules Guesde, 94400 Vitry-sur-Seine, France

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00262, http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00262

*E-mail: Philippe.Lienard@sanofi.com.

(-)-1,4-benzodioxin-5-carboxamide-8-amino-7-chloro-N-(1,4-diazabicyclo[2.2.2]oct-2- ylmethyl)-2,3-dihydro-, hydrochloride (1:2), SL65.0102-10 (1).

……………….. to provide compound 1 (10.3 kg, 76.7%). Compound 1 could be recrystallized in acetone/water (12/2 volumes).

1H-NMR (DMSO-d6, 500 MHz), δ ppm: 3.38 (dd, 1H, J = 12.0 , 6.0 Hz), 3.60-3.45 (m, 7H), 3.65 (t, 1H, J =10.0 Hz), 3.72 (dt, 1H, J =6.0 , 14.0 Hz), 3.83 (m, 2H), 4.01 (m, 1H), 4.33 (m, 2H), 4.39 (m, 2H), 7.37 (s, 1H), 8.35 (t, 1H, J =6.0 Hz). Only 19 protons are observed on 1H spectrum instead of 21 expected. The two amino protons of the molecule are not visible because of chemical exchange with residual water of DMSO-d6 solvent.

13C NMR (DMSO-d6, 125 MHz): δ 38.4, 39.0, 42.8, 43.4, 45.4, 46.5, 54.4, 64.1, 65.1, 109.3, 110.0, 123.2, 130.5, 138.1, 141.8, 165.0.

HRMS: exact mass (by Xevo QToF), MH+ found: 353.1374 (MH+ calculated: 353.1380, difference: -1.7 ppm).

[α]D = -17.9 (C = 0.75, DMSO, t = 23°C) at 589 nm.

Elementary analysis: found C 43.0660%, H 5.5150%, N 12.4792%, calculated C 43.31%, H 5.68%, N 12.63%

1H AND 13C NMR PREDICT

References

1. (a) Hoyer, D.; Clarke, D. E.; Fozard, J. R.; Hartig, P. R.; Martin, G. R.; Mylecharane, E. J.; Saxena, P. R.;Humphrey, P. P. Pharmacol. Rev. 1994, 46 ( 2) 157– 203

   (b) Frazer, A.; Hensler, J. G.Chapter 13: Serotonin Receptors. In Siegel, G. J.; Agranoff, B. W.; Albers, R. W.; Fisher, S. K.; Uhler, M. D., Eds.; Basic Neurochemistry: Molecular, Cellular, and Medical Aspects; Lippincott-Raven, Philadelphia,1999; pp 263– 292.

2. 2.

   Frick, W.; Glombik, H.; Kramer, W.; Heuer, H.; Brummerhop, H.; Plettenburg, O. Novel fluoroglycoside heterocyclic derivatives, pharmaceutical products containing said compounds and the use thereof.

   (a) WO2004/052903, 2004.

   (b) WO2004/052902, 2004.

3. 3.

   Jegham, S.; Koenig, J. J.; Lochead, A.; Nedelec, A.; Guminski, Y.N-[(1,4-diazabicyclo[2.2.2]oct-2-yl)methyl] benzamide derivatives, their preparations and their application in therapeutics.

   (a) FR 2756563 06/13/1995 9506951, 1995.

   (b) US 5663173, 1997; Washington, DC: U.S. Patent and Trademark Office.

“DRUG APPROVALS INT” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

////////SL65.0102-10, SANOFI, 5-HT₃ , 5-HT₄ inhibitor,   neurological disorders

O=C(NCC2CN1CCN2CC1)c4cc(Cl)c(N)c3OCCOc34

Amtolmetin guacil,

ST-679, MED-15, Eufans

CAS 87344-06-7
UNII: 323A00CRO9, 

Molecular Formula, C24-H24-N2-O5, Molecular Weight, 420.463,

2-Methoxyphenyl 1-methyl-5-p-methylbenzoylpyrrole-2-acetoamidoacetate

Glycine, N-((5-benzoyl-1-methyl-1H-pyrrol-2-yl)acetyl)-, 2-methoxyphenyl ester

Trade names: Amtoril®, Artricol®, Artromed®

US 4578481, US 6288241,

MEDOSAN RICERCA S.R.L. [IT/IT]; Via Cancelliera, 12 I-00040 Cecchina RM (IT) (For All Designated States Except US).
SIGMA-TAU INDUSTRIE FARMACEUTICHE RIUNITE S.P.A. [IT/IT]; Viale Shakespeare, 47 I-00144 Roma (IT)

Launched – 1993 ITALY, SIGMA TAU, Non-Opioid Analgesics FOR Treatment of Osteoarthritis, Treatment of Rheumatoid Arthritis,

• Originator sigma-tau SpA
• Class Amino acids; Antipyretics; Nonsteroidal anti-inflammatories; Pyrroles; Small molecules
• Mechanism of Action Cyclooxygenase inhibitors
• • Marketed Inflammation

  Most Recent Events

  • 01 Jun 1999 A meta-analysis has been added to the adverse events section
  • 22 Jul 1995 Launched for Inflammation in Italy (PO)

Amtolmetin guacil is a NSAID which is a prodrug of tolmetin sodium.

Amtolmetin guacil  is a nonacidic prodrug of tolmetin that has similar nonsteroidal antiinflammatory drug (NSAID) properties to those of Tolmetin with additional gastroprotective advantages. The term “nonsteroidal” is used to distinguish these drugs from steroids that have similar eicosanoid-depressing and antiinflammatory actions. Moreover, it possesses a more potent and long-lasting antiinflammatory activity than tolmetin  and is marketed for the treatment of rheumatoid arthritis, osteoarthritis, and juvenile rheumatoid arthritis.

Background

Tolmetin sodium is an effective NSAID approved and marketed for the treatment of rheumatoid arthritis, osteoarthritis and juvenile rheumatoid arthritis. In humans, tolmetin sodium is absorbed rapidly with peak plasma levels observed 30 min after p.o. administration, but it is also eliminated rapidly with a mean plasma elimination t½ of approximately 1 hr. The preparation of slow release formulations or chemical modification of NSAIDs to form prodrugs has been suggested as a method to reduce the gastrotoxicity of these agents.

Amtolmetin guacil is a non-acidic prodrug of tolmetin, having similar NSAID properties like tolmetin with additional analgesic, antipyretic, and gastro protective properties. Amtolmetin is formed by amidation of tolmetin by glycine

Pharmacology

• Almost is absorbed on oral administration. It is concentrated maximum in internal the gastric wall, and highest concentration reached in 2 hours after administration.
• Amtolmetin guacil hydrolysed in to following metabolites Tolmetin, MED5 and Guiacol.
• Elimination will complete in 24 hours. Happens mostly with urine in shape of gluconides products (77%), faecal (7.5%).
• It is advised to take the drug on empty stomach.
• Permanent anti-inflammatory action is continued up to 72 hours, with single administration.

Mechanism of action

Amtolmetin guacil stimulates capsaicin receptors present on gastro intestinal walls, because of presence of vanillic moiety and also releases NO which is gastro protective. It also inhibits prostaglandin synthesis and cyclooxygenase (COX).

Structure of amtolmetin 1 and tolmetin 2.

26171-23-3 TOLMETIN FREE FORM

http://shodhganga.inflibnet.ac.in/bitstream/10603/2173/11/11_chapter%204.pdf

Tolmetin sodium 64490-92-2

Average Mass: 279.2663

26171-23-3 TOLMETIN FREE FORM

1-methyl-5-p-tolylpyrrole-2-acetic acid

Melting point 155-158 °C, IR (KBr, cm-1): 3205 (OH), 2958 (Aliphatic C-H), 1731 (Acid, C=O), 1700 (C=O), 1616 (C=C), 1267 (C-O); 1H NMR (CD3OD, 400 MHz): δ 7.63 ( d, J = 7.8 Hz, 2H), 7.27 (d, J = 7.8 Hz, 2H), 6.63 (d, J = 3.9 Hz, 1H), 6.11 (d, J = 4.3 Hz, 1H), 3.91 (s, 3H), 3.76 (s, 2H), 2.40 (s, 3H); MS (ESI): m/z calcd for C15H15NO3 (M + H): 258.11; found: (M + H) 257.9. (Fig. 4.12 – 4.14)

INNTERMEDIATE

1-methyl-5-p-toluoyl-2-acetamidoacetic acid

Melting point: 200-202° C. IR (KBr, cm-1): 3282 (NH), 3060 (OH), 1741 (Acid, C=O), 1637 (Amide, C=O), 1608 (C=C), 1178 (C-N); 1H NMR (CD3OD, 400 MHz): δ 7.64 ( dd, J =6.3 Hz, 1.9 Hz, 2H), 7.28 (d, J = 7.8 Hz, 2H), 6.65 (d, J = 3.9 Hz, 1H), 6.17 (d, J = 3.9 Hz, 1H), 3.92 (s, 3H), 3.73 (s, 2H), 3.30 (t, J =1.4 Hz, 2H), 2.41(s, 3H); MS (ESI): m/z calcd for C17H18N2O4 (M + H): 315.13; found: (M + H) 315. (Fig. 4.20 – 4.22)

SYNTHESIS

STUDENTS SOME COLOUR………………

1H  and 13 C NMR PREDICT

SYNTHESIS

Amtolmetin guacil (CAS NO.: 87344-06-7), with its systematic name of N-((1-Methyl-5-p-toluoylpyrrol-2-yl)acetyl)glycine o-methoxyphenyl ester, could be produced through many synthetic methods.

Following is one of the synthesis routes: 1-Methyl-5-(4-methylbenzoyl)pyrrole-2-acetic acid (I) is condensed with glycine ethyl ester (II) in the presence of carbonyldiimidazole (CDI) and triethylamine in THF to afford the corresponding acetamidoacetate (III), which is hydrolyzed with NaOH in THF-water yielding 2-[2-[1-methyl-5-(4-methylbenzoyl)pyrrol-2-yl]acetamido]acetic acid (IV). Finally, this compound is esterified with 2-methoxyphenol (guayacol) (V) by means of CDI in hot THF.

PATENT

https://www.google.com/patents/WO1999033797A1?cl=tr

The present invention relates to a new crystalline form of 1- methyl-5-p-toluoylpyrrole-2-acetamidoacetic acid guaiacyl ester, a process for its preparation and to pharmaceutical compositions endowed with antiinflammatory, analgesic and antipyretic activity containing same.

The ester of 1-methyl-5-p-toluoylpyrrole-2-acetamidoacetic acid (hereinafter referred to as MED 15, form 1) is a known compound.

In fact, US Patent 4,882,349 discloses a class of N-mono- substituted and N,N-disubstituted amides of l-methyl-5-p- toluoylpyrrole-2-acetic acid (known as Tolmetin) endowed of anti- inflammatory, analgesic, antipyretic, antisecretive and antitussive properties.

US Patent 4,578,481 claims a specific compound, endowed with valuable pharmacological activity, encompassed in the above- mentioned class, precisely 1-methyl-5-p-toluoylpyrrole-2-acetamido- acetic acid guaiacyl ester (which is MED 15, form 1), and a process for its preparation.

The process disclosed in US 4,578,481 presents some drawbacks, since it is not easily applicable on industrial scale and gives low yields.

According to the above-mentioned process, Tolmetin was reacted with N,N’-carbonyldiimidazole in tetrahydrofuran (THF), and aminoacetic acid ethyl ester hydrochloride was added to the reaction mixture.

Following a complex series of washings in order to remove the unreacted starting compounds, and crystallisation from benzene/ cyclohexane, 1-methyl-5-p-toluoylpyrrole-2-acetamidoace-tic acid ethyl ester was obtained. This compound was subsequently transformed into the corresponding acid.

The acid was reacted with N,N’-carbonyldiimidazole obtaining the corresponding imidazolide, to which a solution of guaiacol in

THF was added.

From the reaction mixture, following several washings, neutralisation and crystallisation from benzene/ cyclohexane MED 15 form 1 was obtained.

The main physico-chemical characteristics of MED 15 form 1 are shown in table 1, left column.

The above mentioned process comprises the following steps:

(a) hydrolysing TOLMETIN 1 methyl ester with an alkaline hydroxide in a basic environment, obtaining TOLMETIN 2 alkaline salt;

(b) condensing 2 with isobutylchloroformate 3 obtaining the mixed anhydride 4;

(c) reacting 4 with glycine 5 obtaining 1-methyl-5-p-toluoylpyrrol-2- acetoamidacetic acid 6;

(d) condensing 6 with isobutylchloroformate 3 obtaining the mixed anhydride 7; and

(e) reacting the mixed anhydride 7 with guaiacol 8 obtaining 9 , MED 15, form 2.

The following non-limiting example illustrates the preparation of MED 15, form 2, according to the process of the present invention.

Preparation of 1-methyl-p-toluoylpirrol-2-acetoammidoacetic acid.

A mixture of 500 mL of toluene, 100 g of Tolmetin ethyl ester and 10 g of Terre deco in 1L flask, was heated to 70° C and maintained at this temperature for 20-30 min, under stirring. The mixture was then filtered on pre-heated buckner, and the solid phase washed with 50 mL of heated toluene. The discoloured toluene solution was transferred in a 2 L flask, 15 g of sodium hydroxide (97%) dissolved in 100 mL of water were added thereto.

The solution was heated at reflux temperature and refluxed for 1 hour. 22 mL of isobutyl alcohol were added to the solution which was heated at reflux temperature; water (about 120 mL) was removed completely with Marcusson’s apparatus arriving up to 104-105°C inner temperature.

To a suspension of Tolmetin sodium, cooled under nitrogen atmosphere to -5°C ± 2°C, 0.2 mL of N-methyl Morpholine were added. Maintaining the temperature at 0°C ± 3°C, 53 mL of isobutyl chloroformate were added dropwise in 5-10 min. After about 1 hour the suspension became fluid. Following 3 hours of reaction at 0°C + 3°C, over the glycine solution previously prepared, the mixed anhydride solution was added dropwise. The glycine solution was prepared in a flask containing 230 mL of demineralised water, 47 g of potassium hydrate (90%), cooling the solution to 20°C ± 2, adding 60 g of glycine, and again cooling to 10°C ± 2°C.

To the glycine solution, the mixed anhydride was added dropwise under stirring, in 5-10 min., maintaining the temperature at 20°C ± 2°C.

At the end of the addition, temperature was left to rise to room temperature, 1 hour later the reaction was complete. To the mixture 325 mL of demineralised water were added, the mixture was brought to pH 6.0 +2 using diluted (16%) hydrochloric acid (about 100 mL).

The temperature of the solution was brought to 73°C ±2°C and the pH adjusted to pH 5.0 ±0.2.

The separation of the two phases was made at hot temperature: the toluene phase was set aside for recovering acid-Tolmetin if any, the water phase was maintained at 73°C ±2°C and brought to pH 4.0 ±0.2 using diluted hydrochloric acid.

At the beginning of the precipitation the solution was slowly brought to pH 3.0 ±0.2 using diluted (16%) hydrochloric acid (100 mL).

The mixture was cooled to 15°C ±3°C and after 30 min. filtered. The solid cake was washed with 2×100 mL of demineralised water, the product was dried at 60°C under vacuum till constant weight. 100 g of 1-methyl-p-toluoylpirrol-2-acetoammidoacetic acid were obtained.

Preparation of MED 15, form 2

To a 2 L flask containing 730 mL of toluene, 100 g of dried compound of the above step were dissolved. To this solution 18.8 g of potassium hydrate (tit. 90%) in 65 mL of water were added.

The solution was dried maintaining the internal temperature at 95-100°C, and cooled to 55-60 °C. A solution of potassium hydrogen carbonate was then added and the resulting mixture was dried maintaining the internal temperature at 105°C ±2°C.

The mixture was cooled under nitrogen atmosphere to 5°C

±2°C, 24 mL of isobutyl alcohol and 0.3 mL of N-methyl morpholine were added thereto.

Maintaining the temperature at 10°C ±3°C, 47 mL of isobutyl-chloroformate were added dropwise in 5-10 minutes. The mixture was left to react for two hours at 10°C ±3°C obtaining an anhydride solution, which was added to a guaiacol solution previously prepared.

The guaiacol solution was prepared by loading in a 2L-flask 295 mL of water, 25 g of potassium hydrate (90%), and 0.3 g of sodium metabisulfite.

At the end of the loading the temperature was brought to 35-40°C.

The anhydride was added dropwise in 5- 10 min and the temperature was left to rise to room temperature.

The suspension was kept under stirring for 1 hour and brought to pH 6.0 ±0.5 with diluted hydrochloric acid. The suspension was heated to 70°C ± 5°C and maintained at pH 3-4 with diluted hydrochloric acid.

The phases were separated while hot. The aqueous phase was discharged, and to the organic phase, 250 mL of water were added.

Maintaining the temperature at 70 ±5°C the solution was brought to pH 8.0 ±0.5 with diluted sodium hydrate, the phases were separated while hot and the acqueous phase was discharged.

The organic phase was washed with 250 mL of water. At 70 ± 5°C the phases were separated. The toluene phase was then cleared with dicalite, filtered and left to crystallise.

The mixture was slowly cooled to 30°C – 35°C, the temperature was then brought to 10 ± 3°C and after 1 hour filtered, washed with toluene (2×100 mL).

The product was brought to dryness at 60°C under vacuum, thus giving 100 g of compound MED 15, form 2.

Theoretical yield: 133.7 g; Yield %: 74.8%.

PATENT

https://www.google.com/patents/WO2000032188A2?cl=un

PATENT

CN-100390144 

PATENT

CN 1827597

Example 1: Steps:

Equipped with a trap, 2000ml four-neck reaction flask with a mechanical stirrer and a thermometer, 加入托 US buna 100.0g (0.358mol) and 500ml of toluene, turned stirred and heated under reflux with toluene with water, drying the solution, when When the internal temperature reaches 95-100 ℃, the solution was cooled to 55-60 ℃, dissolved in 30ml of water was added portionwise 11.5g of potassium bicarbonate was added, and refluxed to remove water, until the internal temperature reaches 105 ± 2 ℃. The mixture was cooled to ice-water bath 5 ± 2 ℃, to which was added 24ml of isobutyl alcohol and 0.3ml N- methylmorpholine. The temperature was maintained at 10 ± 3 ℃, with a pressure-equalizing dropping funnel was added dropwise isobutylchloroformate 45.5ml (0.400mol), 10min addition was complete, so the mixture was 10 ± 3 ℃ 2hr reaction solution to obtain an acid anhydride, it has been prepared dropwise glycine guaiacol ester solution, 5-10min the addition was complete. Glycine guaiacol ester solution was prepared by adding 295ml of water in a 2000ml flask, 27g of potassium hydroxide (82%) and 0.3g of sodium metabisulfite, stirring to dissolve, the temperature was controlled at 10 ± 3 ℃, to which was added 82.7g (0.38mol) glycine guaiacol ester hydrochloride and prepared. Dropwise addition, the temperature was raised to room temperature, the reaction 2hr, diluted with 16% hydrochloric acid to adjust the mixture to pH 6.0 ± 0.5. The suspension was heated to 70 ± 5 ℃, and then 16% diluted hydrochloric acid to adjust the pH to 3.5 to 4.5, while hot liquid separation, discarding the aqueous phase, the organic phase was added to 250ml of water, maintaining the temperature at 70 ± 5 ℃ with dilute (2N) sodium hydroxide solution to adjust the solution to pH 8.0 ± 0.5, and then hot liquid separation, aqueous phase was discarded. With 2 × 250ml The organic phase was washed with water, the phases were separated at 70 ± 5 ℃, then clean the toluene organic phase through celite, cooled to room temperature, allowed to set freezer cooling crystallization, filtration, filter cake washed with 2 × 50ml of cold washed with toluene, and dried in vacuo at 60 ℃ to constant weight to give 1- methyl-5-p-toluoylpyrrole-2-acetamido acid guaiacol ester crude 135.5 g, yield 90%. The crude product was recrystallized from acetone to give 1-methyl-5-acyl-2-acetyl-p-toluene amino acid ester of guaiacol boutique 127.9 g, yield 94.4%, mp128.7 ~ 131.9 ℃. Elemental analysis: C, 68.53%; H, 5.76%; N, 6.65%. IR spectrum (KBr tablet method): 3318,3142,2963,1778,1652,1626,1605,1500,1480,1456,13731255 and 1153cm-1.

Example 2: Procedure: equipped with a water separator, 2000ml four-neck reaction flask with a mechanical stirrer and a thermometer, 加入托 US buna 100.0g (0.358mol) and 500ml of toluene, turned stirred and heated under reflux with toluene with water , drying the solution, when the internal temperature reaches 95-100 ℃, the solution was cooled to 55-60 ℃, dissolved in 30ml of water was added portionwise 11.5g of potassium bicarbonate was added, and refluxed to remove water, until the internal temperature reaches 105 ± 2 ℃. The mixture was cooled to ice-water bath 5 ± 2 ℃, to which was added 24ml of isobutyl alcohol and 0.3ml N- methylmorpholine. The temperature was maintained at 10 ± 3 ℃, with a pressure-equalizing dropping funnel dropwise isopropyl 46.5ml (0.41mol), 10-15min addition was complete, the mixture was allowed at 10 ± 3 ℃ reaction 2hr derived anhydride solution, it would have been prepared dropwise to glycine guaiacol ester solution, 5-10min the addition was complete. Glycine guaiacol ester solution was prepared by adding 295ml of water in a 2000ml flask, 27g of potassium hydroxide (82%) and 0.3g of sodium metabisulfite, stirring to dissolve, the temperature was controlled at 10 ± 3 ℃, to which was added 82.7g (0.38mol) glycine guaiacol ester hydrochloride and prepared. Dropwise addition, the temperature was raised to room temperature, the reaction 2hr, diluted with 16% hydrochloric acid to adjust the mixture to pH 6.0 ± 0.5. The suspension was heated to 70 ± 5 ℃, and then 16% diluted hydrochloric acid to adjust the pH to 3.5 to 4.5, while hot liquid separation, discarding the aqueous phase, the organic phase was added to 250ml of water, maintaining the temperature at 70 ± 5 ℃ with dilute (2N) sodium hydroxide solution to adjust the solution to pH 8.0 ± 0.5, and then hot liquid separation, aqueous phase was discarded. With 2 × 250ml The organic phase was washed with water, the phases were separated at 70 ± 5 ℃, then clean the toluene organic phase through celite, cooled to room temperature, allowed to set freezer cooling crystallization, filtration, filter cake washed with 2 × 50ml of cold washed with toluene, and dried in vacuo at 60 ℃ to constant weight to give 1- methyl-5-p-toluoylpyrrole-2-acetamido acid guaiacol ester crude 138.5 g, yield 92%. The crude product was recrystallized from acetone to give 1-methyl-2-acyl-5-toluene acetaminophen acid ester guaiacol boutique 128.8 grams.

Example 3: equipped trap, 2000ml four-neck reaction flask with a mechanical stirrer and a thermometer, 加入托 US buna 100.0g (0.358mol) and 500ml of toluene, turned stirred and heated under reflux with toluene with water, dried solution, when the internal temperature reaches 95-100 ℃, the solution was cooled to 55-60 ℃, dissolved in 30ml of water was added portionwise 10-12.5g potassium bicarbonate solution, refluxing was continued for removal of water, until the internal temperature reaches 105 ± 2 ℃. The mixture was cooled to ice-water bath 5 ± 2 ℃, added thereto 20-30ml of isobutyl alcohol 0.2-0.5mlN- methylmorpholine. The temperature was maintained at 10 ± 3 ℃, with a pressure-equalizing dropping funnel was added dropwise isobutylchloroformate 40.5-48.5ml, 10-15min addition was complete, so the mixture was 10 ± 3 ℃ 2hr reaction solution to obtain an acid anhydride, it has been prepared dropwise glycine guaiacol ester solution, 5-10min the addition was complete. Glycine guaiacol ester solution was prepared by adding 295ml of water in a 2000ml flask, 25-30g of potassium hydroxide (82%) or 15-17 grams of sodium hydroxide and sodium metabisulfite 0.2-0.5g or insurance powder, stirring to dissolve the temperature is controlled at 10 ± 3 ℃, to which is added 80-84g glycine guaiacol ester hydrochloride and prepared. Dropwise addition, the temperature was raised to room temperature, the reaction 2hr, the mixture was adjusted with dilute hydrochloric acid to pH 6.0 ± 0.5. The suspension was heated to 70 ± 5 ℃, with dilute hydrochloric acid to adjust the pH to 3.5 to 4.5, while hot liquid separation, discarding the aqueous phase, the organic phase was added to 250-280ml of water, maintaining the temperature at 70 ± 5 ℃ , adjusted with dilute sodium hydroxide solution and the solution to pH 8.0 ± 0.5, and then hot liquid separation, aqueous phase was discarded. With 2 × 250ml The organic phase was washed with water, the phases were separated at 70 ± 5 ℃, then clean the toluene organic phase through celite, cooled to room temperature, allowed to set freezer cooling crystallization, filtration, filter cake washed with 2 × 50ml of cold washed with toluene, and dried in vacuo at 60 ℃ to constant weight to give 1- methyl-5-p-toluoylpyrrole-2-acetamido acid guaiacol ester crude 130-139 grams. The crude product was recrystallized from acetone to give 1-methyl-5-acyl-2-acetyl-p-toluene amino acid ester boutique guaiacol 120-129 grams.

PATENT

Indian Pat. Appl. (2010), IN 2008MU01617

DETAILED DESCRIPTION OF THE INVENTION
The present invention provides safe, environment friendly, economically viable and commercially feasible processes for the production of Amtolmetin guacil. There are two methods for the preparation of Amtolmetin guacil. The processes for the production of Amtolmetin guacil (I) comprise:
Method-1:
Step-A:- Treating 2-methoxy phenol of Formula VI with 2-(benzyloxycarbonylamino) acetic acid of Formula VII in the presence of an organic base and a condensing agent in chlorinated solvent to yield 2-methoxyphenyl-2- (benzyloxycarbonylamino) acetate of Formula V.
Step-B:- Acid addition salt of 2-methoxyphenyl -2-aminoacetate of Formula II may be prepared by treating 2-methoxyphenyl-2- (benzyloxycarbonylamino) acetate of Formula V with an acid and followed by crystallization in aprotic solvent.
7

Step-C):- l-methyl-5-p-toluoylpyrrole-2-acetic acid of Formula III is reacted with a condensing agent to form-activated moiety, which is reacted with acid addition salt of 2-methoxyphenyl -2-aminoacetate of Formula II in chlorinated solvent to produce Arntolmetin guacil of formula (I).
In a preferred embodiment of present invention, condensing agent used in step-A is selected from group consisting of dicyclohexylcarbodiimide, N, N’-carbonyl diimidazole, hydroxy benzotriazole. The most preferred condensing agent is Dicyclohexyl carbodiimide for the reaction.
The solvent used in present invention is selected from the group consisting of but not limited to toluene, methylene chloride, chloroform, water miscible ethers such as tetrahydrofuran, 1,4-dioxane, the most preferred solvent for the reaction methylene dichloride.
In another embodiment of the present invention, the reaction is performed in the presence of an organic base. The organic base is selected from the group consisting of trimethylamine, triethylamine, N-methyl morpholine, N-methylpyrrolidinone, 4-dimethyl Aminopyridine; the most preferred base is 4-dimethyl Aminopyridine.
In a preferred embodiment of present invention, the non-polar solvent used in step-B is selected from group consisting of ethers, hexanes, aromatic hydrocarbons and esters.
In another preferred embodiment of present invention, the most suitable solvents are esters.
In another preferred embodiment of present invention, condensing agent used in step-C is selected from group consisting of dicyclohexylcarbodiimide, N, N’-carbonyl diimidazole, hydroxy benzotriazole. The most preferred condensing agent is N, N’-carbonyl diimidazole for the conversion of the reaction.
8

The solvent used in present invention is selected from the group consisting of but not limited to toluene, methylene chloride, chloroform, water miscible ethers such as tetrahydrofuran, 1,4-dioxane, the most preferred solvent for the reaction methylene dichloride.
In yet another embodiment of the present invention, the reaction is performed at a temperature in the range of -20°C to 50°C. Most preferred temperature range for the reaction is (-) 10°C to 0°C.
Method-2:
Treating 2-(2-(I-methyl-5- (4-methylbenzoyl)-lH-pyrrol-2-yl) acetamido) acetic acid with 2-methoxy phenol in presence of condensing reagent and an organic base to obtain Amtolmetin guacil.
In a preferred embodiment of present invention, the condensing agent used is selected from group consisting of dicyclohexyicarbodiimide, hydroxy benzotriazole or a mixture thereof. The most preferred condensing agent is Dicvclohexyl carbodiimide for the aforementioned reaction.
The solvent used in present invention is selected from the group consisting of but not limited to toluene, methylene chloride, chloroform, water miscible ethers such as tetrahydrofuran. 1,4-dioxane, the most preferred solvent for the reaction is methylene dichloride.
In another embodiment of the present invention, the reaction is performed in the presence of an organic base. The organic base is selected from the group consisting of triethylamine, triethylamine, N-methyl morpholine, N-methylpyrrolidinone, 4-dimethyl Aminopyridine; the most preferred base is 4-dimethyl Aminopyridine.
9

In yet another embodiment of the present invention, the reaction is performed at a temperature in the range of -20°C to 50°C. Most preferred temperature range for the reaction is (-) 10°C to 0°C.
In another embodiment of present invention, crude amtolmetin guacil is directly purified using polar and non-polar solvent or a mixture thereof. The most preferred solvents are Isopropanol and toluene.
The following non-limiting examples illustrate specific embodiments of the present invention. They are, however, not intended to be limiting the scope of present invention in anyway.
Preparation of Amtolmetin guacil: Example-1;
Charged MDC (600 ml) and N-benzyloxycarbonyl glycine (100 gm) in a 2L-4NRBF under N2 atmosphere. Reaction mass was cooled down to -5°C. Added N, N’-dicyclohexylcarbodiimide solution (108.5 gm in 300 ml MDC) at-5°C to 0°C. Maintained temperature of reaction for 10 minutes at -5°C to 0°C. Added guaiacol solution (59.36 gm in 180 ml MDC) at -5°C to 0°C followed by addition of N, N-dimethyl aminopyridine (1 gm) at -5°C to 0°C. Monitored the reaction over TLC till the completion of reaction, while maintaining reaction at 0°C. Filtered the undissolved Dicyclohexyl urea and washed the solids with methylene dichloride (125 ml X 2). Collected filtrate and washing. Washed methylene dichloride with water (1000 ml X 2), lN-NaOH (500 ml X 2) and 1% HC1 solution (500 ml X 2), water (500 ml X 2) respectively. Organic methylene dichloride layer was dried over anhydrous sodium sulphate. Filtered sodium sulphate and collected methylene dichloride filtrate. Distilled out methylene dichloride under vacuum below 40°C to get oil. HPLC purity :> 90%
10

Added 33% HBr in acetic acid solution (262,5 gm) into reaction vessel at 25-30°C. Monitored the reaction over TLC till the completion of reaction, while maintaining the reaction at 25-30°C. Added ethyl acetate (1200 ml) slowly at 25-30°C after completion of reaction. Stirred the resultant slurry for 2.5 hours at 25-30°C for complete crystallization. Filtered the solids and washed it with ethyl acetate (200 ml). Dried solids at 50-55°C. Dry weight: 102 gm. HPLC Purity: >98%
Example-2:
Charged MDC (1400 ml) and N, N’-carbonyl di imidazole (69.34 gm) into a 3L-4NRBF under N2 atmosphere. Cooled it down to -15°C. Charged Tolmetin acid (100 gm) slowly into reaction vessel at -10° ± 5°C. Monitored the progress of reaction of over HPLC. After completion of reaction, charged slowly 2-methoxyphenyl-2- (benzyloxy carbonylamino) acetate hydrobromide salt (112.05 gm) at -10° ± 5°C.Monitored the reaction over HPLC. After completion of reaction, washed the organic layer with water (300 ml), 1% NaOH solution (100 ml) and water (300 ml X 2) respectively at 3-8°C. Treated organic layer with activated carbon (2.5 gm) and filtered over hyflow bed. Washed hyflow bed with methylene dichlonde (100 ml X 2). Distilled out methylene dichloride below 40°C under vacuum and stripped off traces with toluene (100 ml X 2) at 50-55°C. Charged toluene (600 ml) and Isopropanol (50ml). Heated the mass to 63-68°C. Stirred the clear solution at 63-68°C for 1 hour. Cooled it down slowly to 30°C followed by further cooling to 5°C. Stirred the resultant slurry for 3 hours at 0-5°C. Filtered solids and washed with toluene (100 ml X 2). Dried solids at 55-60°C under vacuum. Dry Weight: 130 gm. HPLC Purity: >99%
Example-3:
Charged MDC (333 liter) and 2-(2-(l-methyl-5- (4-methylbenzoyl)-lH-pyrrol-2-yl) acetamido) acetic acid (55.5 Kg) in reactor under N2 atmosphere at 25-30°C. Cool down reaction mass to -15 to -12°C. Added a freshly prepared solution of N, N’-dicyclohexyl
11

carbodiimide (47.39 Kg in 166.5 liter) slowly at -10° ± 5°C within 1 hour. Rinsed the addition funnel with MDC (55.5 liter) and added it to the reaction at -10° ± 5°C. Added guaiacol solution (24.14 Kg in 99.9 liter MDC) to the reaction mass at -10° ± 5°C within 1 hour. Rinsed the addition funnel with MDC (11.1 liter) and added to the reaction -10° ± 5°C. Charged N, N’-dimethyl aminopyridine (0.555 Kg) at -15°C. Maintained temperature of reaction mass at -10° ± 5°C for 3 hours. Monitored the reaction over TLC, After the completion of reaction, filtered the dicyclohexyl urea and washed the solids with MDC (55.5L X 2). Collected MDC filtrate and wash it with water (166.5 L X 2). Collected MDC layer and treated it with activated carbon (2.77 Kg) and filtered through sparkler. Washed the sparkler with MDC (111 L). Distilled out MDC below 40°C under vacuum and stripped off traces with toluene (55.5 L X 2) at 50-55°C. Charge toluene (333L) and Isopropanol (27.75 L). Heated reaction mass to 63-68°C to get a clear solution. Stirred the clear solution at 63-68°C for 1 hour. Cooled it down slowly to 30°C followed by further cooling to 20oC. Stirred the resultant slurry for 2 hours at 17-20°C. Filtered the solids and washed with toluene (55.5 L X 3). Dried the solids at 55-60°C under vacuum. Dry Weight: 48 Kg. HPLC Purity:>99%

PAPER

Synthesis and Process Optimization of Amtolmetin: An Antiinflammatory Agent^†

Abstract

Efforts toward the synthesis and process optimization of amtolmetin guacil 1 are described. High-yielding electrophilic substitution followed by Wolf−Kishner reduction are the key features in the novel synthesis of tolmetin 2 which is an advanced intermediate of 1.

Amtolmetin guacil

Clinical data
ATC code	none
Identifiers
IUPAC name[show]
Synonyms	ST-679
CAS Number	87344-06-7
PubChem (CID)	65655
ChemSpider	59091
UNII	323A00CRO9
KEGG	D07453
ChEMBL	CHEMBL1766570
ECHA InfoCard	100.207.038
Chemical and physical data
Formula	C24H24N2O5
Molar mass	420.458 g/mol
3D model (Jmol)	Interactive image
SMILES[hide] O=C(c1ccc(n1C)CC(=O)NCC(=O)Oc2ccccc2OC)c3ccc(cc3)C

/////////Amtolmetin guacil, ST-679, MED-15, Eufans,  87344-06-7, Amtoril®, Artricol®, Artromed®, амтолметин гуацил , أمتولمتين غواسيل , 呱氨托美丁

n1(c(ccc1CC(NCC(=O)Oc1c(cccc1)OC)=O)C(=O)c1ccc(cc1)C)C

FOTAGLIPTIN

CAS 1312954-58-7

342.37, C₁₇ H₁₉ F N₆ O

(R)-2-((3-(3-amino-piperidin-1-yl)-6-methyl-5-oxo-1,2,4-piperazine-4(5H)-yl)methyl)-4-fluorobenzonitrile,

BENZOATE 1403496-40-1

(R) 2- Methyl-5-oxo-1,2,4-triazin-4 (5H) -yl) methyl) -4-fluorobenzonitrile (3- benzoate (compound benzoate A), of the formula: the C _{. 17} the H ₁₉ the FN _{. 6} O · the C _{. 7} the H _{. 6} O ₂ , molecular weight: 464.49.

useful as a dipeptidyl peptidase IV (DPPIV) inhibitor for treating diabetes, particularly type 2 diabetes

Dipeptidyl peptidase IV inhibitor,

a DPPIV inhibitor, being developed by Chongqing Fochon, with licensee Shenzhen Salubris Pharmaceuticals, for treating type 2 diabetes mellitus. In January 2017, fotagliptin benzoate was reported to be in phase 1 clinical development. The compound of the present invention was first disclosed in WO2011079778. See WO2015110078 and WO2015110077, claiming crystalline polymorphic form of the DPPIV inhibitor.

• Originator Chongqing Fochon Pharmaceutical
• Class Antihyperglycaemics
• Mechanism of Action CD26 antigen inhibitors
• Shanghai Fosun Pharma Transfers Development Rights in New Diabetes & Cancer Therapies to Swiss-Greek Firm

Research Article

Development and validation of a UPLC–MS/MS method for simultaneous determination of fotagliptin and its two major metabolites in human plasma and urine

Zhenlei Wang¹, Ji Jiang¹, Pei Hu¹ & Qian Zhao*^,1

*Author for correspondence: zhaoqianp@qq.com

Aim: Fotagliptin is a novel dipeptidyl peptidase IV inhibitor under clinical development for the treatment of Type II diabetes mellitus. The objective of this study was to develop and validate a specific and sensitive ultra-performance liquid chromatography (UPLC)–MS/MS method for simultaneous determination of fotagliptin and its two major metabolites in human plasma and urine. Methodology & results: After being pretreated using an automatized procedure, the plasma and urine samples were separated and detected using a UPLC-ESI–MS/MS method, which was validated following the international guidelines. Conclusion: A selective and sensitive UPLC–MS/MS method was first developed and validated for quantifying fotagliptin and its metabolite in human plasma and urine. The method was successfully applied to support the clinical study of fotagliptin in Chinese healthy subjects.

PATENT

WO2011079778

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2011079778&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

PATENT

WO2015110078

compound A can be prepared according to the method disclosed in PCT / CN2010 / 080370, the specific synthesis route and the main reaction conditions are as follows:

Example 1 Preparation of 1-bromo-4-fluoro-2- (isothiocyanatomethyl) benzene (2)

To a DMF solution (20 ml) of 1-bromo-2- (bromomethyl) -4-fluorobenzene (1,5.36 g, 20.0 mmol) was added sodium iodide (1.20 g, 8.00 mmol) and potassium thiocyanate (3.88 g, 40.0 mmol). After the mixture was heated to 80C under nitrogen atmosphere for 12 hours, it was cooled to room temperature, 100 ml of water was added thereto, and extracted with ethyl acetate (50 mL x 2). The combined organic layers were washed with saturated brine, dried over anhydrous magnesium sulfate, The concentrate was concentrated by suction to give a crude product, and the residue was purified by silica gel column chromatography (eluent: petroleum ether) to give 1-bromo-4-fluoro-2- (isothiocyanatomethyl) benzene (2).

Example 2 Preparation of N- (2-bromo-5-fluorobenzyl) hydrazinocarbothioamide (3)

A solution of hydrazine hydrate (80%, 2.22 g, 35.5 mmol) in 1,4-dioxane (20 mL) was cooled to 0 ° C and 1-bromo-4-fluoro-2- (isothiocyanate Yl) benzene (2,3.16 g, 12.8 mmol) in 1,4-dioxane (5 ml). The mixture was stirred at room temperature for 2 h, to which was added 100 ml of ice water, solid precipitated, filtered, washed with water and dried over phosphorus pentoxide overnight to give N- (2-bromo-5-fluorobenzyl) hydrazinothiocarb Amide (3).

MS: m / z, 278 (100%, M + 1), 280 (100%), 300 (10%, M + 23), 302 (10%).

Example 3 Preparation of methyl 2- (2- (2-bromo-5-fluorobenzylaminothioformamide) hydrazino) propionate (4)

N- (2-bromo-5-fluorobenzyl) hydrazinocarbothioamide (3, 1.12 g, 4.00 mmol) was added successively to a solution of pyruvic acid (352 mg, 4.00 mmol) in methanol And the residue was extracted with ethyl acetate (150 ml). The organic layer was washed successively with water, saturated sodium bicarbonate solution and saturated brine, and dried over anhydrous magnesium sulphate (MgSO4). The organic layer was washed with water, Dried, and concentrated by suction filtration to give methyl 2- (2- (2-bromo-5-fluorobenzylaminothioformamide) hydrazino) propionate (4).

MS: m / z, 362 (100%, M + 1), 364 (100%), 384 (60%, M + 23), 386 (60%).

Example 4 4- (2-Bromo-5-fluorobenzyl) -6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin- (5)

Sodium methoxide (0.4 M), freshly prepared from sodium (273 mg, 11.88 mmol) and dry methanol (30 ml), was dissolved in 30 ml of methanol, and methyl 2- (2- (2-bromo-5-fluorobenzylamino sulfide The mixture was heated to reflux for 22 h. Most of the solvent was distilled off. The residue was diluted with 100 ml of water, adjusted to pH = 1-2 with 2N concentrated hydrochloric acid, and the residue was extracted with ethyl acetate. The extract was washed with brine, dried over anhydrous sodium sulfate and concentrated by suction to give a crude product which was purified by silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 20% -30%) to give 4- (2-bromo-5-fluorobenzyl) -6-methyl-3-thioxo-3,4-dihydro- ) -one (5).

MS: m / z, 330 (65%, M + 1), 332 (60%, M + 23).

Example 5 Preparation of 4- (2-bromo-5-fluorobenzyl) -6-methyl-3- (methylthio) -1,2,4-triazin-5 (4H) preparation

A mixture of 4- (2-bromo-5-fluorobenzyl) -6-methyl-3-thioxo-3,4-dihydro- , 914 mg, 2.77 mmol) was suspended in ethanol (15 ml), followed by addition of sodium hydroxide (111 mg, 2.77 mmol) and methyl iodide (787 mg, 5.54 mmol). The reaction mixture was diluted with 100 ml of water and extracted with ethyl acetate (30 ml x 2). The combined layers were washed with saturated brine, dried over anhydrous magnesium sulfate, concentrated by suction, and the residue was recrystallized from the residue. Silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 20-25%) afforded 4- (2-bromo-5-fluorobenzyl) -6-methyl-3- (methylthio) -l, 2,4-triazin-5 (4H) -one (6).

¹ the H NMR (400MHz, of DMSO, ppm by): [delta] 7.73 (m, IH), 7.16 (br, IH), 7.05 (D, IH), 5.09 (S, 2H), 2.56 (S, 3H), 2.32 ( S, 3H).

MS: m / z, 344 (100%, M + l), 346 (100%).

Example 6 (R) -tert-Butyl 1- (4- (2-bromo-5-fluorobenzyl) -6-methyl-5-oxo-4,5-dihydro- -triazin-3-yl) piperidine-3-carbamate (8)

A solution of 4- (2-bromo-5-fluorobenzyl) -6-methyl-3- (methylthio) -1,2,4-triazin-5 (4H) Mmol) and (R) -tert-butylpiperidine-3carbamate (7,208 mg, 1.04 mmol) for 5 min and heated to 135 ° C for 13 h under nitrogen. The reaction mixture was purified by column chromatography on silica gel (R) -tert-Butyl 1- (4- (2-bromo-5-fluorobenzyl) -6-methyl-5- Oxo-4,5-dihydro-1,2,4-triazin-3-yl) piperidine-3-carbamate (8).

MS: m / z, 496 (100%, M + l), 498 (100%).

Example 7 (R) -tert-Butyl 1- (4- (2-cyano-5-fluorobenzyl) -6-methyl-5-oxo-4,5-dihydro- Triazin-3-yl) piperidine-3-carbamate (9)

To a mixture of sodium carbonate (53 mg, 0.50 mmol), palladium acetate (3 mg, 0.013 mmol) and N-methylpyrrolidone 0.5 ml was added 3 drops of isopropanol and 2 drops of water, and the mixture was stirred at room temperature for 5 minutes, (R) -tert-Butyl 1- (4- (2-bromo-5-fluorobenzyl) -6-methyl-5-oxo-4,5-dihydro- – triazin-3-yl) piperidine-3-carbamate (8,246mg, 0.496mmol) in NMP (1.0mL), and heated to 140 ℃, then add the K ₄ [of Fe (the CN) _{. 6} ] 3H · ₂ O (209mg, 0.496 mmol), was heated at 140 ℃ 12h, cooled to room temperature, water was added 10ml, extracted with ethyl acetate (20mL × 2), the combined organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, (R) -tert-Butyl l- (4- (2-cyano-5- (2-fluoro-4-methoxyphenyl) Fluoro-benzyl) -6-methyl-5-oxo-4,5-dihydro-1,2,4-triazin-3-yl) piperidine-3-carbamate (9).

MS: m / z, 418 (20%), 443 (100%, M + 1), 465 (95%, M + 23).

Example 5 Preparation of compound A (R) -2 – ((3- (3-aminopiperidin- 1 -yl) -6-methyl- -yl) methyl) -4-fluorobenzonitrile (10)

To a solution of (R) -tert-Butyl 1- (4- (2-cyano-5-fluorobenzyl) -6-methyl-5-oxo-4,5-dihydro- Yl) piperidine-3-carbamate (9,37 mg) in 1 ml of methylene chloride was added 0.5 ml of trifluoroacetic acid and the mixture was stirred at room temperature for 1 hour, neutralized with a saturated sodium hydrogencarbonate solution, (Eluent: dichloromethane / methanol / aqueous ammonia = 92: 6: 2), in order to obtain (10ml × 3), the organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo to give the crude product, which was purified by silica gel column chromatography Methyl) -5-oxo-1,2,4-triazin-4 (5H) -yl) methyl) -4-fluorobenzonitrile (10), i.e. Compound A.

¹ the H NMR (400MHz, of DMSO, ppm by): [delta] 7.96 (m, IH), 7.36 (br, IH), 7.29 (D, IH), 5.23 (S, 2H), 3.15 (m, 3H), 2.72 ( 2H), 2.23 (s, 3H), 1.78 (d, 1H), 1.64 (d, 1H), 1.47 (m, 1H), 1.12 (m, 1H).

MS: m / z, 343 (100%, M + l).

Methyl-5-oxo-1,2,4-triazin-4 (5H) -yl) -2-oxoquinoline-3- Methyl) -4-fluorobenzonitrile benzoate (Compound A benzoate)

Configuration 95% ethanol solution: 500mL beaker by adding 228mL ethanol, add 12mL of water, stir well, spare.

60g of 95% ethanol, 120mL of 95% ethanol, stirring, dissolving, filtering, washing with 95% ethanol 18ml; to make the 500mL reaction flask, The ethanolic solution of benzoic acid was added dropwise at an internal temperature of 15 ° C. After completion of the dropwise addition, 95% ethanol was washed and dried under reduced pressure to constant weight to give 42.4 g of (R) -2- (3- (3-aminopiperidin-1-yl) -6-methyl- 1,2,4-triazin-4 (5H) -yl) methyl) -4-fluorobenzonitrile benzoate (the product).

Melting point determination: Instrument: Tianjin University Precision Instrument Factory YRT-3 melting point instrument.

Detection method: Take appropriate amount of this product, small study, 60 ° C, 2 hours of vacuum drying, according to the Chinese Pharmacopoeia 2010 edition two appendix Ⅵ C determination of the product melting point of 95 ℃ -115 ℃.

(5H) -benzoic acid was isolated from (R) -2- (3- (3-aminopiperidin-l- yl) -6-methyl- Methyl) -4-fluorobenzonitrile benzoate 0.1g, according to the Chinese Pharmacopoeia 2010 edition of two Appendix Ⅲ “General Identification Test” under the “benzoate” test method for testing, set 10ml volumetric flask, Add water and dilute the solvent to the mark, shake, the precise amount of 5ml to 10ml beaker, adjust the solution of phenolphthalein was neutral, drop of ferric chloride solution, were observed ocher precipitation. At the same time do blank control test, the results: multiple batches of samples of benzoic acid identification test results were positive, reagent blank does not interfere with the determination of specificity.

Identification HPLC: chromatographic conditions for the introduction of the Eclipse Plus C the Agilent ₁₈ column (5μm, 4.6х250mm), detection wavelength of 229nm, mobile phase of acetonitrile: 0.1% phosphoric acid = 7: 3, a flow rate of 1.0ml / min, The injection volume was 20μl.

The compound A (7.5 mg) of Example 8 was dissolved in a 50 mL volumetric flask, diluted with 70% aqueous acetonitrile and diluted to the mark, shaken as a solution of the compound A reference substance; and 12.5 mg of benzoic acid in a 25 mL volumetric flask, With a volume ratio of 70% acetonitrile aqueous solution and diluted to the mark, take 1mL in 25mL volumetric flask, with volume ratio of 70% acetonitrile aqueous solution and diluted to the mark, shake, as benzoic acid reference substance solution; take this product 10mg In a 50mL volumetric flask, with a volume ratio of 70% acetonitrile aqueous solution dissolved and diluted to the mark, shake, as the product A benzoic acid salt of the test solution. Respectively, the precise amount of the reference solution and the test solution 20μl, according to high performance liquid chromatography (Chinese Pharmacopoeia 2010 edition two Appendix VD), according to the chromatographic conditions of injection, chromatogram shown in Figure 1, Method.

The results showed that the retention time of the main peak was the same as the retention time of the reference substance, and the content of compound A and benzoic acid was calculated by the peak area. The molar ratio of compound A and benzoic acid was 1: 1.

Infrared absorption spectrum identification: the United States NICOLET AVATAR 330FT-IR infrared spectrometer, in accordance with the Chinese Pharmacopoeia 2010 edition two Appendix IVC correction, take the amount of goods, using KBr tablet method for determination of the product of the infrared diffraction pattern (Figure 2 shown) to wave number cm & lt ^-1 , he said in 3419.75cm ^-1 , 2936.46cm ^-1 , 2230.38cm ^-1 , 1683.28cm ^-1 , 1609.47cm ^-1 , 1511.65cm ^-1 , 1419.44cm ^-1 , 829.18cm ^-1 , 722.67cm ^-1 characteristic absorption peak, 0.2cm error is ± ^-1 .

NEW PATENT

WO-2017008684

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2017008684&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=FullText

Shenzhen Salubris Pharmaceuticals Co Ltd, α-Crystal form of compound A, preparation method thereof, and pharmaceutical composition comprising same

Step BN- (2-Bromo-5-fluorobenzyl) hydrazinocarbothioamide (3)

//////////FOTAGLIPTIN BENZOATE, FOTAGLIPTIN , PHASE 1, 1403496-40-1, 1312954-58-7

N[C@@H]1CCCN(C1)C3=NN=C(C)C(=O)N3Cc2cc(F)ccc2C#N

 

(S)-N-(2-bromo-6-methoxypyridin-4-yl)-2-hydroxy-2,4-dimethylpentanamide

(S)-N-(2-Bromo-6-methoxypyridin-4-yl)-2-hydroxy-2,4-dimethylpentanamide

CAS 1433905-44-2

Nonsteroidal antiandrogens

HPLC (Daicel Chiralpak IC 250 × 4.6 mm, 5 μm, n-heptane/IPA/TFA 930:70:1, 1 mL·min^–1, 25 °C, UV 210 nm): t_r (minor) = 5.1 min, t_r (major) = 5.9 min.

NMR ¹H (400 MHz, DMSO-d₆): 10.0 (sl, 1H); 7.73 (s, 1H); 7.33 (s, 1H); 5.70 (sl, 1H); 3.80 (s, 3H); 1.79–1.67 (m, 2H); 1.49 (dd, J = 13.6 and 5.2 Hz, 1H); 1.32 (s, 3H); 0.89 (d, J = 6.4 Hz, 3H); 0.78 (d, J = 6.4 Hz, 3H).

NMR ¹³C (100 MHz, DMSO-d₆): 176.7, 164.0, 149.5, 138.1, 111.1, 74.9, 53.9, 48.6, 27.5, 24.3, 23.6, 23.2.

ESI-HRMS(m/z) calcd for C₁₃H₂₀BrN₂O₃⁺ [M+H]⁺ 331.0652 found 331.0654.

PATENT

WO 2013064681

Synthesis 71

(R)-2-Hydroxy-2,4-dimethyl-pentanoic acid (2-bromo-6-methoxy-pyridin-4-yl)-amide

(Compound 71A)

(S)-2-Hydroxy-2,4-dimethyl-pentanoic acid (2-bromo-6-methoxy-pyridin-4-yl)-amide

(Compound 71 B)

The two enantiomers of the racemic mixture prepared in Synthesis 41 were separated by HPLC (high pressure liquid chromatography) on a chiral stationary phase Chiralpak type la, Chiral Technologies, diameter 2 cm, length 25 cm, eluting with 93/7 (v/v) heptane / isopropanol containing 0.1 % (v/v) trifluoroacetic acid. The flow rate was 18 mL/minute. The injection volume was 1 mL of a solution of 20 mg of the racemic mixture dissolved in a 1 /1 (v/v) mixture of heptane / isopropanol. The retention times of the two enantiomers were 8.38 minutes and 9.70 minutes. After 6 injections, 40 mg of the two enantiomers were obtained as oils after solvent evaporation.

Analysis 71

Further analysis was performed using chiral HPLC (Chiralpak type la, Chiral

Technologies, 250 x 4, 6 mm, eluent 93/7 (v/v) heptane / isopropanol containing 0.1 % (v/v) trifluoroacetic acid with a flow rate of 1 mL/minute for 20 minutes. Compound 71 A had a retention time of 6.77 minutes, and Compound 71 B had a retention time of 8.71 minutes.

The absolute configuration of Compound 71 B was determined using X-ray diffraction (XRD), and found to be the (S) configuration. Accordingly, Compound 71 A was determined to be in the (R) configuration.

^a(a) H₂O₂, TFA, 80%. (b) H₂SO₄, HNO₃, 73%. (c) Fe, NH₄Cl, EtOH, 51%. (d) MeOH, NaOH, MW 120 °C, 7 bar, 84%. (e) DCC, pyruvic acid, NMP, 29%. (f) i-BuMgCl, THF, 34%. (g) Chiral HPLC separation, 45%.

PAPER

http://pubs.acs.org/doi/abs/10.1021/acs.oprd.6b00392

Process Development and Crystallization in Oiling-Out System of a Novel Topical Antiandrogen

Sébastien Daver, Nicolas Rodeville, Francois Pineau, Jean-Marie Arlabosse, Christine Moureou, Franck Muller, Romain Pierre, Karinne Bouquet, Laurence Dumais, Jean-Guy Boiteau^* , and Isabelle Cardinaud

Nestlé Skin Health R&D Les Templiers, 2400 Route des colles BP 87, 06902 Sophia-Antipolis CEDEX, France

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00392

*Telephone: +33 4 92 95 29 48; E-mail: Jean-Guy.Boiteau@galderma.com.

ACS Editors’ Choice – This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

An efficient route to (S)-N-(2-bromo-6-methoxypyridin-4-yl)-2-hydroxy-2,4-dimethylpentanamide 1, a new topical antiandrogen, is described. The target compound has been manufactured on kilogram scale with an overall yield of 25% (HPLC purity 98.8% and >99% ee) from citrazinic acid. The key amide coupling between aminopyridine 4 and α-hydroxy-acid 6 was performed using a temporary protecting group to facilitate the acyl chloride formation. Aminopyridine 4 was manufactured from commercially available citrazinic acid via dibromide formation using phosphorus(V) oxybromide followed by mono S_NAr reaction with sodium methoxide and a final Hofmann rearrangement. Enantiopure α-hydroxy-acid 6 was obtained using an enantioselective cyanosilylation followed by salt resolution with (S)-α-methyl benzylamine. The absolute configuration of compound 1 was determined with anomalous scattering and the final crystallization of API was performed after seeding a liquid–liquid mixture below the monotectic temperature and afforded a crystalline powder presenting a “desert rose” shape clusters.

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

///////Nonsteroidal antiandrogens,

Brc1cc(NC(=O)[C@@](C)(O)C(C)C)cc(OC)n1

Telcagepant, MK-0974

• Molecular FormulaC₂₆H₂₇F₅N₆O₃
• Average mass566.523 Da

• OriginatorMerck & Co
• ClassAntimigraines; Piperidines
• Mechanism of ActionCalcitonin gene-related peptide receptor antagonists

Migraine is a neurovascular disorder characterized by severe, debilitating, and throbbing unilateral headache. Though a leading cause of disability, it is a highly prevalent disease with a clear unmet medical need. With the significant progress achieved in the field of pathophysiology in the past decades, to date, it is well recognized that the neuropeptide calcitonin gene-related peptide (CGRP), which is expressed mainly in the central and peripheral nervous system, plays a crucial role in migraine. Antagonism of CGRP receptors, as a potential new therapy for the treatment of migraine, could offer the advantage of avoiding the cardiovascular liabilities associated with other existing antimigraine therapies.

Telcagepant (INN) (code name MK-0974) is a calcitonin gene-related peptide receptor antagonist which was an investigational drug for the acute treatment and prevention of migraine, developed by Merck & Co. In the acute treatment of migraine, it was found to have equal potency to rizatriptan^[1] and zolmitriptan^[2] in two Phase III clinical trials. The company has now terminated development of the drug.

Mechanism of action

The calcitonin gene-related peptide (CGRP) is a strong vasodilator primarily found in nervous tissue. Since vasodilation in the brain is thought to be involved in the development of migraine and CGRP levels are increased during migraine attacks, this peptide may be an important target for potential new antimigraine drugs.

Telcagepant acts as a calcitonin gene-related peptide receptor (CRLR) antagonist and blocks this peptide. It is believed to constrict dilated blood vessels within the brain.^[3]

Termination of a clinical trial

A Phase IIa clinical trial studying telcagepant for the prophylaxis of episodic migraine was stopped on March 26, 2009 after the “identification of two patients with significant elevations in serum transaminases”.^[4] A memo to study locations stated that telcagepant had preliminarily been reported to increase the hepatic liver enzyme alanine transaminase (ALT) levels in “11 out of 660 randomized (double-blinded) study participants.” All study participants were told to stop taking the medication.^[5]

On July 29, 2011, it was reported that Merck & Co. were discontinuing the clinical development program for telcagepant. According to Merck, “[t]he decision is based on an assessment of data across the clinical program, including findings from a recently completed six-month Phase III study”.^[6]

CLIP

CLIP

CLIP

Asymmetric Synthesis of Telcagepant

http://pubs.acs.org/doi/abs/10.1021/jo101704b

References

Telcagepant

Clinical data
Routes of administration	Oral
ATC code	none
Legal status
Legal status	Development terminated
Pharmacokinetic data
Biological half-life	5–8 hours
Identifiers
IUPAC name[show]
CAS Number	781649-09-0
PubChem (CID)	11319053
IUPHAR/BPS	703
ChemSpider	9494017
UNII	D42O649ALL
KEGG	D09391
ChEMBL	CHEMBL236593
Chemical and physical data
Formula	C26H27F5N6O3
Molar mass	566.5283 g/mol
3D model (Jmol)	Interactive image

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

///////////Telcagepant, MK-0974

C1CC(C(=O)N(CC1C2=C(C(=CC=C2)F)F)CC(F)(F)F)NC(=O)N3CCC(CC3)N4C5=C(NC4=O)N=CC=C5

BMS-960

PRECLINICAL

(S)-1-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic Acid

3-Piperidinecarboxylic acid, 1-[(2S)-2-hydroxy-2-[4-[5-[3-phenyl-4-(trifluoromethyl)-5-isoxazolyl]-1,2,4-oxadiazol-3-yl]phenyl]ethyl]-, (3S)-

(S)-1-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic Acid

CAS 1265321-86-5 FREE FORM

FREE FORM 528.48, C₂₆ H₂₃ F₃ N₄ O₅

CAS 1265323-40-7 HCL SALT

BASIC PATENT WO201117578, 2011, (US Patent 8399451)

Sphingosine-1-phosphate (S1P) is the endogenous ligand for the sphingosine-1-phophate receptors (S1P_1–5) and triggers a number of cellular responses through their stimulation. S1P and its interaction with the S1P receptors play a significant role in a variety of biological processes including vascular stabilization, heart development, lymphocyte homing, and cancer angiogenesis. Agonism of S1P₁, especially, has been shown to play an important role in lymphocyte trafficking from the thymus and secondary lymphoid organs, inducing immunosuppression, which has been established as a novel mechanism of treatment for immune diseases and vascular diseases

Sphingosine-1 -phosphate (SlP) has been demonstrated to induce many cellular effects, including those that result in platelet aggregation, cell proliferation, cell morphology, tumor cell invasion, endothelial cell and leukocyte chemotaxis, endothelial cell in vitro angiogenesis, and lymphocyte trafficking. SlP receptors are therefore good targets for a wide variety of therapeutic applications such as tumor growth inhibition, vascular disease, and autoimmune diseases. SlP signals cells in part via a set of G protein-coupled receptors named SlPi or SlPl, SlP₂ or S1P2, SlP₃ or S1P3, SlP₄ Or S1P4, and SlP₅ or S1P5 (formerly called EDG-I, EDG-5, EDG-3, EDG-6, and EDG-8, respectively).

SlP is important in the entire human body as it is also a major regulator of the vascular and immune systems. In the vascular system, SlP regulates angiogenesis, vascular stability, and permeability. In the immune system, SlP is recognized as a major regulator of trafficking of T- and B-cells. SlP interaction with its receptor SlPi is needed for the egress of immune cells from the lymphoid organs (such as thymus and lymph nodes) into the lymphatic vessels. Therefore, modulation of SlP receptors was shown to be critical for immunomodulation, and SlP receptor modulators are novel immunosuppressive agents.

The SlPi receptor is expressed in a number of tissues. It is the predominant family member expressed on lymphocytes and plays an important role in lymphocyte trafficking. Downregulation of the SlPi receptor disrupts lymphocyte migration and homing to various tissues. This results in sequestration of the lymphocytes in lymph organs thereby decreasing the number of circulating lymphocytes that are capable of migration to the affected tissues. Thus, development of an SlPi receptor agent that suppresses lymphocyte migration to the target sites associated with autoimmune and aberrant inflammatory processes could be efficacious in a number of autoimmune

Among the five SlP receptors, SlPi has a widespread distribution and is highly abundant on endothelial cells where it works in concert with SIP3 to regulate cell migration, differentiation, and barrier function. Inhibition of lymphocyte recirculation by non-selective SlP receptor modulation produces clinical immunosuppression preventing transplant rejection, but such modulation also results in transient bradycardia. Studies have shown that SlPi activity is significantly correlated with depletion of circulating lymphocytes. In contrast, Sl P3 receptor agonism is not required for efficacy. Instead, SIP3 activity plays a significant role in the observed acute toxicity of nonselective SlP receptor agonists, resulting in the undesirable cardiovascular effects, such as bradycardia and hypertension. (See, e.g., Hale et al, Bioorg. Med. Chem. Lett., 14:3501 (2004); Sanna et al., J. Biol. Chem., 279: 13839 (2004); Anliker et al., J. Biol. Chem., 279:20555 (2004); Mandala et al., J. Pharmacol. Exp. Ther., 309:758 (2004).)

An example of an SlPi agonist is FTY720. This immunosuppressive compound FTY720 (JPI 1080026-A) has been shown to reduce circulating lymphocytes in animals and humans, and to have disease modulating activity in animal models of organ rejection and immune disorders. The use of FTY720 in humans has been effective in reducing the rate of organ rejection in human renal transplantation and increasing the remission rates in relapsing remitting multiple sclerosis (see Brinkman et al., J. Biol. Chem., 277:21453 (2002); Mandala et al., Science, 296:346 (2002); Fujino et al., J.

Pharmacol. Exp. Ther., 305:45658 (2003); Brinkman et al, Am. J. Transplant., 4: 1019 (2004); Webb et al., J. Neuroimmunol, 153: 108 (2004); Morris et al., Eur. J. Immunol, 35:3570 (2005); Chiba, Pharmacology & Therapeutics, 108:308 (2005); Kahan et al., Transplantation, 76: 1079 (2003); and Kappos et al., N. Engl. J. Med., 335: 1124 (2006)). Subsequent to its discovery, it has been established that FTY720 is a prodrug, which is phosphorylated in vivo by sphingosine kinases to a more biologically active agent that has agonist activity at the SlPi, SIP3, SlP₄, and SIP5 receptors. It is this activity on the SlP family of receptors that is largely responsible for the pharmacological effects of FTY720 in animals and humans. [0007] Clinical studies have demonstrated that treatment with FTY720 results in bradycardia in the first 24 hours of treatment (Kappos et al, N. Engl. J. Med., 335: 1124 (2006)). The observed bradycardia is commonly thought to be due to agonism at the SIP₃ receptor. This conclusion is based on a number of cell based and animal experiments. These include the use of SIP3 knockout animals which, unlike wild type mice, do not demonstrate bradycardia following FTY720 administration and the use of SlPi selective compounds. (Hale et al., Bioorg. Med. Chem. Lett., 14:3501 (2004); Sanna et al., J. Biol. Chem., 279: 13839 (2004); and Koyrakh et al., Am. J. Transplant, 5:529 (2005)).

The following applications have described compounds as SlPi agonists: WO 03/061567 (U.S. Patent Publication No. 2005/0070506), WO 03/062248 (U.S. Patent No. 7,351,725), WO 03/062252 (U.S. Patent No. 7,479,504), WO 03/073986 (U.S. Patent No. 7,309,721), WO 03/105771, WO 05/058848, WO 05/000833, WO 05/082089 (U.S. Patent Publication No. 2007/0203100), WO 06/047195, WO 06/100633, WO 06/115188, WO 06/131336, WO 2007/024922, WO 07/109330, WO 07/116866, WO 08/023783 (U.S. Patent Publication No. 2008/0200535), WO 08/029370, WO 08/114157, WO 08/074820, WO 09/043889, WO 09/057079, and U.S. Patent No. 6,069,143. Also see Hale et al., J. Med. Chem., 47:6662 (2004).

There still remains a need for compounds useful as SlPi agonists and yet having selectivity over Sl P3.

Applicants have found potent compounds that have activity as SlPi agonists. Further, applicants have found compounds that have activity as SlPi agonists and are selective over SIP3. These compounds are provided to be useful as pharmaceuticals with desirable stability, bioavailability, therapeutic index, and toxicity values that are important to their drugability.

SYNTHESIS

(S)-1-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid, HCl (BMS-960). CAS 1265323-40-7

(S)-1-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid, HCl (BMS-960)

¹H NMR (400 MHz, DMSO-d₆) δ 12.88 (br. s, 1H), 10.5 (br. s, 1H), 8.14 (d, J = 8.6 Hz, 2H), 7.72 (d, J = 8.4 Hz, 2H), 7.69–7.57 (m, 5H), 6.43 (br. s., 1H), 5.37 (d, J = 10.8 Hz, 1H), 3.89–3.60 (m, 2H), 3.50–2.82 (m, 6H), 2.14–1.99 (m, 1H), 1.97–1.75 (m, 1H), 1.63–1.35 (m, 1H);

¹³C NMR (101 MHz, CDCl₃) δ 172.8, 168.5, 164.0, 161.6, 155.4, 156.2, 131.2, 129.0, 128.9, 127.4, 127.2, 125.5, 124.3, 122.2, 111.6, 66.6. 63.0, 52.9, 52.2, 38.8, 25.0, 21.7;

¹⁹F NMR (376 MHz, DMSO-d₆) δ −54.16;

Anal. calcd for C₂₆H₂₃F₃N₄O₅·HCl: C, 54.71; H, 4.36; N, 9.80. Found: C, 54.76; H, 3.94; N, 9.76;

HRMS (ESI) m/e 529.17040 [(M + H)⁺, calcd for C₂₆ H₂₄ N₄ O₅ F₃ 529.16933].

PATENT

WO 2011017578

Example 14

(S)-l-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-l,2,4- oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid

Preparation 14A: (3S)-Ethyl l-(2-(4-cyanophenyl)-2-hydroxyethyl)piperidine-3- carboxylate

(14A)-isomer A (14A)-isomer B [00210] To a mixture of (S)-ethyl piperidine-3-carboxylate (1.3 g, 8.27 mmol) in toluene (50 mL) was added 4-(2-bromoacetyl)benzonitrile (2.4 g, 10.71 mmol). The reaction mixture was stirred overnight. LCMS indicated completion of reaction. MeOH (10 mL) was added to the mixture, followed by the portionwise addition of sodium borohydride (0.313 g, 8.27 mmol). After 1 hour, LCMS show complete reduction to the desired alcohol. The reaction was quenched with water. The reaction mixture was diluted with ethyl acetate and washed with saturated NaCl. The organic layer was dried with MgSO₄, filtered, concentrated, and purified on a silica gel cartridge using an EtOAc/hexanes gradient to yield 2.0 g of solid product. The product was separated by chiral HPLC (Berger SFC MGIII instrument equipped with a CHIRALCEL® OJ (25 x 3 cm, 5 μM). Temp: 30 ⁰C; Flow rate: 130 mL/min; Mobile phase: C(V(MeOH +

0.1%DEA) in 9: 1 ratio isocratic:

[00211] Peak 1 (Isomer A): RT = 2.9 min. for (S)-ethyl l-((S)-2-(4-cyanophenyl)-2- hydroxyethyl)piperidine-3-carboxylate (>99% d.e.). The absolute and relative stereochemistry of compound 14A-isomer A was assigned (S,S) by X-ray crystal structure (see Alternative Route data). ¹H NMR (400 MHz, CDCl₃) δ ppm 7.63 (2 H, m, J=8.35 Hz), 7.49 (2 H, m, J=8.35 Hz), 4.77 (1 H, dd, J=10.55, 3.52 Hz), 4.17 (2 H, q, J=7.03 Hz), 3.13 (1 H, d, J=9.23 Hz), 2.53-2.67 (3 H, m), 2.44 (2 H, dd, J=18.68, 9.89 Hz), 2.35 (1 H, dd, J=12.74, 10.55 Hz), 1.87-2.01 (1 H, m), 1.71-1.82 (1 H, m), 1.52-1.70 (2 H, m), 1.28 (3 H, t, J=7.03 Hz).

[00212] Peak 2 (Isomer B): RT = 3.8 min for (S)-ethyl l-((R)-2-(4-cyanophenyl)-2- hydroxyethyl)piperidine-3-carboxylate (>99% d.e.). The absolute and relative stereochemistry of 14A-isomer B was assigned (S,R) based on the crystal structure of 14A-isomer A. ¹H NMR (400 MHz, CDCl₃) δ ppm 7.63 (2 H, m, J=8.35 Hz), 7.49 (2 H, m, J=8.35 Hz), 4.79 (1 H, dd, J=10.55, 3.52 Hz), 4.16 (2 H, q, J=7.03 Hz), 2.69-2.91 (3 H, m), 2.60-2.68 (1 H, m), 2.56 (1 H, dd, J=12.30, 3.52 Hz), 2.36 (1 H, dd, J=12.52, 10.77 Hz), 2.25 (1 H, t, J=8.79 Hz), 1.65-1.90 (3 H, m), 1.52-1.64 (1 H, m, J=12.69, 8.49, 8.49, 4.17 Hz), 1.27 (3 H, t, J=7.25 Hz).

[00213] (S)-Ethyl l-((S)-2-(4-cyanophenyl)-2-hydroxyethyl)piperidine-3-carboxylate (14A-isomer A) was carried forward to make Example 14 and (S)-ethyl l-((R)-2-(4- cyanophenyl)-2-hydroxyethyl)piperidine-3-carboxylate (14A-isomer B) was carried forward to make Example 15.

Preparation 14B: (S)-Ethyl l-((S)-2-hydroxy-2-(4-((Z)-N’-hydroxycarbamimidoyl) phenyl)ethyl)piperidine-3 -carboxylate

[00214] To a mixture of ((S)-ethyl l-((S)-2-hydroxy-2-(4-((Z)-N’- hydroxycarbamimidoyl) phenyl)ethyl)piperidine-3 -carboxylate (14A-Isomer A) (58 mg, 0.192 mmol) and hydroxylamine hydrochloride (26.7 mg, 0.384 mmol) in 2-propanol (10 mL) was added sodium bicarbonate (64.5 mg, 0.767 mmol). The reaction mixture was heated at 85 ⁰C. The reaction mixture was diluted with ethyl acetate and washed with sat NaCl. The organic layer was dried with MgSO₄, filtered, and concentrated to yield 56 mg. MS (M+l) = 464. HPLC Peak RT = 1.50 minutes.

Preparation 14C: (S)-Ethyl l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl) isoxazol-5-yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylate

[00215] 3-Phenyl-4-(trifluoromethyl)isoxazole-5-carbonyl fluoride, InM-G (214 mg, 0.78 mmol) was dissolved in acetonitrile (5.00 mL). DIEA (0.272 mL, 1.555 mmol) and (S)-ethyl- 1 -((S)-2-hydroxy-2-(4-((Z)-N’-hydroxycarbamimidoyl) phenyl)ethyl)- piperidine-3-carboxylate (261 mg, 0.778 mmol) were added. The reaction mixture was stirred for 2 hours, then IM TBAF in THF (0.778 mL, 0.778 mmol) was added. The reaction mixture was stirred overnight at room temperature. The reaction mixture was filtered and purified by HPLC in three batches. HPLC conditions: PHENOMENEX® Luna C18 5 micron column (250 x 30mm); 25-100% CH₃CN/water (0.1% TFA); 25 minute gradient; 30 mL/min. Isolated fractions with correct mass were partitioned between EtOAc and saturated NaHCO₃ with back extracting aqueous layer once. The organic layer was dried with MgSO₄, filtered, and concentrated to give 155mg of (S)- ethyl l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-l,2,4- oxadiazol-3-yl)phenyl)ethyl) piperidine-3-carboxylate. ¹H NMR (400 MHz, MeOH-d₃) δ ppm 8.04 (2 H, d, J=8.13 Hz), 7.55-7.60 (2 H, m), 7.41-7.54 (5 H, m), 4.81 (1 H, ddd, J=8.35, 4.06, 3.84 Hz), 3.96-4.10 (2 H, m), 2.82-3.08 (1 H, m), 2.67-2.82 (1 H, m), 2.36- 2.61 (3 H, m), 2.08-2.33 (2 H, m), 1.73-1.87 (1 H, m, J=8.54, 8.54, 4.45, 4.17 Hz), 1.32- 1.70 (3 H, m), 1.09-1.19 (3 H, m). MS (m+l) = 557. HPLC Peak RT = 3.36 minutes. Purity = 99%.

Example 14: [00216] (S)-Ethyl l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5- yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylate (89 mg, 0.16 mmol) was heated at 50 ⁰C in 6N HCl (5 mL) in acetonitrile (5 mL). The reaction mixture was stirred overnight and then filtered and purified by HPLC. HPLC conditions:

PHENOMENEX® Luna C 18 5 micron column (250 x 30mm); 25-100% CH₃CN/water (0.1% TFA); 25 minute gradient; 30 mL/min. Isolated fractions with correct mass were freeze-dried overnight to yield 36 mg of (S)-l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4- (trifluoromethyl)isoxazol-5-yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl) piperidine-3- carboxylic acid as a TFA salt. ¹H NMR (400 MHz, MeOH-d₃) δ ppm 8.23 (2 H, d, J=8.35 Hz), 7.65-7.74 (4 H, m), 7.54-7.65 (3 H, m), 5.29 (1 H, t, J=7.03 Hz), 4.00 (1 H, br. s.), 3.43-3.75 (1 H, m), 3.34-3.41 (2 H, m), 2.82-3.24 (2 H, m), 2.26 (1 H, d, J=I 1.86 Hz), 1.84-2.14 (2 H, m), 1.52-1.75 (1 H, m). MS (m+1) = 529. HPLC Peak RT = 3.24 minutes. Purity = 98%. Example 14-Alternate Synthesis Route 1

Preparation 14D (Alternate Synthesis Route 1): (S)-4-(Oxiran-2-yl)benzonitrile

[00217] To 800 mL of 0.2M, pH 6.0 sodium phosphate buffer in a 2 L flask equipped with an overhead stirrer was added D-glucose (38.6 g, 1.2 eq), β-nicotinamide adenine dinucleotide, free acid (1.6 g, mmol), glucose dehydrogenase (36 mg, 3.2 kU,

CODEXIS® GDH- 102, 90 U/mg), and enzyme KRED-NADH-110 (200 mg,

CODEXIS®, 25 U/mg). The vessels containing the reagents above were rinsed with 200 mL of fresh sodium phosphate buffer and added to the reaction which was stirred to dissolution and then heated to 40 ⁰C. To this mixture was added a solution of 2-bromo- 4′-cyanoacetophenone (40 g, 178.5 mmol) in 100 mL DMSO through an addition funnel in about 30 min. The container was rinsed with 20 mL DMSO and the rinse was added to the reactor. A pH of 5.5-6.0 was maintained by adding 1 M NaOH through a fresh addition funnel (total volume of 200 mL over 6h) after which HPLC showed complete consumption of the starting material. The reaction mixture was extracted with 800 mL MTBE x 2 and the combined extracts were washed with 300 mL of 25% brine. The crude alcohol was transferred to a 3L 3-neck flask and treated with solid NaOtBu (34.3 g, 357 mmol) stirring for 1 h and then additional NaOtBu (6.9 g, 357 mmol) and stirring for 30 min. The reaction mixture was filtered and the solution was washed with 300 mL 0.2 M pH 6.0 sodium phosphate buffer, brine, and then the solvent was removed in vacuo and the resulting white solid was dried in a vacuum oven to give (S)-4-(oxiran-2- yl)benzonitrile (23 g, 90% yield, 100% e.e.). ¹H NMR (400 MHz, CDCl₃) δ ppm 7.62 (2 H, d), 7.35 (2 H, d), 3.88 (1 H, dd), 3.18 (1 H, app t), 2.73 (1 H, dd) Purity = 99%.

[00218] Chiral HPLC was done on a CHIRALP AK® AD-RH 4.6x150mm (Daicel Chemical Industries Ltd.) column using gradient of solvent A (10 mM NH₄OAc in water/acetonitrile, 90: 10) and solvent B (10 mM NH₄OAc in water/acetonitrile, 10:90) with 70% to 90% in 40 min at a flow rate of 0.5 ml/min at ambient temperature. The detection employed UV at 235 nm. The retention times are as follows:

[00219] Peak 1 (Isomer A): RT = 16.7 min. for (S)-4-(oxiran-2-yl)benzonitrile

[00220] Peak 2 (Isomer B): RT = 14.0 min. for (R)-4-(oxiran-2-yl)benzonitrile Preparation of 14A-isomer A (Alternate Synthesis Route 1): (S)-Ethyl l-((S)-2-(4- cyanophenyl)-2 -hydroxy ethyl)piperidine-3-carboxylate

(14A)-isomer A

[00221] (S)-4-(Oxiran-2-yl)benzonitrile (10.00 g, 68.9 mmol), (S)-ethyl piperidine-3- carboxylate (10.83 g, 68.9 mmol) and iPrOH (100 mL) was charged into a round bottom flask under N₂. After heating at 55 ⁰C for 4 hours, 4-dimethylaminopyridine (1.683 g, 13.78 mmol) was then added. The reaction mixture was then heated to 50 ⁰C for an additional 12 hours. At this time HPLC indicated the starting material was completely converted to the desired product. The reaction mixture was then cooled to room temperature. EtOAc (120 ml) was added, followed by 100 ml of water. The organic layer was separated, extracted with EtOAc (2x 100 mL) and concentrated under vacuo to give a crude product. The crude product was recrystallized from EtOH/EtOAc/H₂O (3/2/2) (8ml/lg) to give a crystalline off-white solid 14A-alt (15 g, 72% yield, 99.6% e.e.). The absolute and relative stereochemistry was determined by single X-ray crystallography employing a wavelength of 1.54184 A. The crystalline material had an orthorhombic crystal system and unit cell parameters approximately equal to the following:

a = 5.57 A α = 90.0°

b = 9.7l A β = 90.0°

c = 30.04 A γ = 90.0°

Space group: P2₁2₁2₁

Molecules/asymmetric unit: 2

Volume/Number of molecules in the unit cell = 1625 A³

Density (calculated) = 1.236 g/cm³

Temperature 298 K.

Preparation 14E (Alternate Route 1): (S)-Ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2- (4-cyanophenyl)ethyl)piperidine-3-carboxylate

[00222] To a mixture of (S)-ethyl 1 -((S)-2-(4-cyanophenyl)-2-hydroxy ethyl) piperidine-3-carboxylate (17.0 g, 56.2 mmol) and DIPEA (17.68 ml, 101 mmol) in CH₂Cl₂ (187 mL) was added tert-butyldimethylsilyl trifluoromethanesulfonate (16 ml, 69.6 mmol) slowly. The reaction was monitored with HPLC. The reaction completed in 2 hours. The reaction mixture (a light brown solution) was quenched with water, the aqueous layer was extracted with DCM. The organic phase was combined and dried with Na₂SO₄. After concentration, the crude material was further purified on a silica gel cartridge (33Og silica, 10-30% EtOAc/hexanes gradient) to afford a purified product (S)- ethyl 1 -((S)-2-(tert-butyldimethylsilyloxy)-2-(4-cyanophenyl)ethyl) piperidine-3 – carboxylate (22.25 g, 53.4 mmol, 95 % yield). ¹H NMR (400 MHz, CDCl₃) δ ppm 7.61 (2 H, d), 7.45 (2 H, d), 4.79 (1 H, m), 4.15 (2 H, m), 2.88 (1 H, m), 2.75 (1 H, m), 2.60 (1 H, dd), 2.48 (1 H, m), 2.40 (1 H, dd), 2.33 (1 H, tt), 2.12 (1 H, tt), 1.90 (1 H, m), 1.68 (1 H, dt), 1.52 (1 H, m), 1.48 (1 H, m), 1.27 (3 H, t), 0.89 (9 H, s), 0.08 (3 H, s), -0.07 (3 H, s).

Preparation 14F (Alternate Route 1): (S)-Ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2- (4-((Z)-N’-hydroxycarbamimidoyl)phenyl)ethyl)piperidine-3-carboxylate

[00223] (S)-Ethyl- 1 -((S)-2-(tert-butyldimethylsilyloxy)-2-(4-cyanophenyl)ethyl) piperidine-3-carboxylate (31.0 g, 74.4 mmol) was dissolved in EtOH (248 mL).

Hydroxylamine (50% aq) (6.84 ml, 112 mmol) was added and stirred at room temperature overnight. Then all volatiles were removed with ROTA VAPOR®. The residue was purified with on a silica gel cartridge (33Og silica, 0-50% EtOAc/hexanes gradient) to give (S)-ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2-(4-((Z)-N’- hydroxycarbamimidoyl)phenyl)ethyl)piperidine-3-carboxylate (31 g, 68.9 mmol, 93 % yield) as a white foam. ¹H NMR (400 MHz, CDCl₃) δ ppm 8.38 (1 H, br s), 7.58 (2 H, d), 7.37 (2 H, d), 4.88 (2 H, br s), 4.81 (1 H, m), 4.13 (2 H, m), 2.96 (1 H, m), 2.82 (1 H, m), 2.61 (1 H, dd), 2.51 (1 H, m), 2.42 (1 H, dd), 2.32 (1 H, tt), 2.13 (1 H, dt), 1.91 (1 H, m), 1.66 (1 H, dt), 1.58 (1 H, m), 1.48 (1 H, m), 1.27 (3 H, t), 0.89 (9 H, s), 0.08 (3 H, s), -0.09 (3 H, s). Preparation 14G (Alternate Route 1): (S)-Ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2- (4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-l,2,4-oxadiazol-3- yl)phenyl)ethyl)piperidine-3-carboxylate

[00224] (S)-Ethyl- 1 -((S)-2-(tert-butyldimethylsilyloxy)-2-(4-((Z)-N’- hydroxycarbamimidoyl)phenyl)ethyl)piperidine-3-carboxylate (32.6g, 72.5 mmol) was dissolved in acetonitrile (145 ml) (anhydrous) and cooled to ~3 ⁰C with ice-bath. 3- phenyl-4-(trifluoromethyl)isoxazole-5-carbonyl chloride (19.98 g, 72.5 mmol) was dissolved in 5OmL anhydrous acetonitrile and added dropwise. The internal temperature was kept below 10 ⁰C during addition. After addition, the reaction mixture was allowed to warm to room temperature. At 30 minutes, HPLC showed completion of the first reaction step. The reaction mixture was re-cooled to below 10 ⁰C. DIEA (18.99 ml, 109 mmol) was added slowly. After the addition, the reaction mixture was heated up to 55 ⁰C for 17 hr s. HPLC/LCMS showed completion of the reaction. The solvents were removed by ROTA VAPOR®. The residue was stirred in 25OmL 20% EtOAc/hexanes and the DIPEA HCl salt precipitated from solution and was removed via filtration. The filtrate was concentrated and purified using a silica gel cartridge (3X33Og silica, 0-50%

EtOAc/hexanes gradient). (S)-ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2-(4-(5-(3- phenyl-4-(trifluoromethyl)isoxazol-5-yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3- carboxylate (43g, 64.1 mmol, 88 % yield) was obtained a light yellow oil. ¹H NMR (400 MHz, CDCl₃) δ ppm 8.16 (2 H, d), 7.68 (2 H, d), 7.57 (5 H, m), 4.85 (1 H, m), 4.14 (2 H, m), 2.95 (1 H, m), 2.82 (1 H, m), 2.64 (1 H, dd), 2.51 (1 H, m), 2.49 (1 H, dd), 2.35 (1 H, tt), 2.14 (1 H, dt), 1.91 (1 H, m), 1.66 (1 H, dt), 1.57 (1 H, m), 1.48 (1 H, m), 1.27 (3 H, t), 0.92 (9 H, s), 0.11 (3 H, s), -0.05 (3 H, s).

Example 14 (Alternate Route 1): (S)-l-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4- (trifluoromethyl)isoxazol-5-yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3- carboxylic acid

[00225] (S)-Ethyl l-((S)-2-(tert-butyldimethylsilyloxy)-2-(4-(5-(3-phenyl-4- (trifluoromethyl)isoxazol-5-yl)-l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3- carboxylate (42g, 62.6 mmol) was dissolved in dioxane (150 ml) and treated with 6M HCl (150 ml). The reaction mixture was heated to 65 ⁰C for 6 hours (the reaction was monitored with HPLC, EtOH was distilled out to push the equilibrium forward). Dioxane was removed and the residue was redissolved in ACN/water and lyophilized separately to give crude (S)-l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl) isoxazol-5-yl)- l,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid, HCl, (37g crude foamy solid). The crude solid (36 g, 63.7 mmol) was suspended in acetonitrile (720 mL) and heated to 60 ⁰C and water (14.4 mL) was added dropwise. A clear solution was obtained, which was cooled to room temperature and concentrated to a viscous oil, treated with ethyl acetate (1.44 L) with vigorously stirring, heated to 60 ⁰C, and cooled to room temperature. (S)-l-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)- l,2,4-oxadiazol-3-yl)phenyl)ethyl) piperidine-3-carboxylic acid, HCl (28g, 49.3 mmol, 77 % yield) was collected and vacuum dried. Characterization of product by ¹H NMR and chiral HPLC matched Example 14 prepared in previous synthesis.

Preparation of Intermediate (14A)-isomer A-Alternate Route 2; 2-Steps: (S)-Ethyl 1- ((S)-2-(4-cyanophenyl)-2-hydroxyethyl)piperidine-3-carboxylate

(14A)-isomer A

Step 1 : Preparation (14D) (Alternate Route 2): (S)-Ethyl l-(2-(4-cyanophenyl)-2- oxoethyl)piperidine-3-carboxylate hydrobromide

(14D)-isomer A

[00226] To a solution of commercially available (S)-ethyl piperidine-3-carboxylate (10 g, 63.6 mmol) in 200 mL toluene was added 4-(2-bromoacetyl)benzonitrile (17g, 76 mmol). The reaction mixture was stirred overnight. The next day, the precipitated solid was collected by filtration and washed with ethyl acetate (x3) and dried under vacuum to give 15.2g of (S)-ethyl l-(2-(4-cyanophenyl)-2-oxoethyl)piperidine-3-carboxylate hydrobromide. MS (M+ 1) = 301. HPLC Peak RT = 1.51 minutes.

Step 2: Preparation of 14 A-isomer A (Alternate Route 2): (S)-Ethyl l-((S)-2-(4- cyanophenyl)-2-hydroxyethyl)piperidine-3 -carboxylate

[00227] Phosphate buffer (1100 mL, BF045, pH 7.0, 0. IM) was added into two liter jacketed glass reactor. The temperature of the reactor was adjusted to 20 ⁰C with the help of a circulator and the reaction mixture was stirred with a magnetic stirrer. Dithiothretol (185.2 mg, 1 mM), magnesium sulfate (288.9 mg, 2 mM), and D-glucose (11.343 g, 62.95 m moles) were added into the reactor. (5^*)-Ethyl l-(2-(4-cyanophenyl)-2-oxoethyl) piperidine-3 -carboxylate HBr salt (12 g, 31.47 m moles dissolved in 60 mL DMSO) was added into the reactor slowly with continuous stirring, β-nicotinamide adenine dinucleotide phosphate sodium salt (NADP), 918.47 mg, glucose dehydrogenase, 240 mg (total 18360 U, 76.5 U/mg, ~ 15U/mL, Amano Lot. GDHY1050601) and KRED-114, 1.2 g (CODEXIS® assay 7.8 U/mg of solid), were dissolved in 2.0 mL, 2.0 mL and 10 ml of the same buffer, respectively. Next, NADP, GDH and KRED-114 were added to the reactor in that order. The remaining 26 mL of same buffer was used to wash the NADP, GDH and KRED-114 containers and buffer was added into the same reactor. The starting pH of the reaction was 7.0 which decreased with the progress of the reaction and was maintained at pH 6.5 during the course of the reaction (used pH stat, maintained with IM NaOH). The reaction was run for 4.5 hours and immediately stopped and extracted with ethyl acetate. The ethyl acetate solution was evaporated under reduced pressure and weight of the dark brown residue was 12.14 g. The product was precipitated with dichloromethane and heptane to give 9 g of crude product which was further purified by dissolving it in minimum amount of dichloromethane and re-precipitating by the addition of excess amount of heptane to give 5.22 g. The process was repeated to give an additional 2.82 g of highly pure product for a total of 8.02 g of de > 99.5%.

[00228] Chiral HPLC was done on a CHIRALP AK® AD-RH 4.6x150mm (Daicel Chemical Industries Ltd.) column using gradient of solvent A (10 mM NH₄OAc in water/acetonitrile, 90: 10) and solvent B (IO mM NH₄OAc in water/acetonitrile, 10:90) with 70% to 90% in 40 min at a flow rate of 0.5 ml/min at ambient temperature. The detection was done by UV at 235 nm. The retention times are as follows: [00229] Peak 1 (14A-isomer A): RT = 20.7 min. for (S)-ethyl l-((S)-2-(4- cyanophenyl)-2-hydroxyethyl)piperidine-3-carboxylate.

[00230] Peak 2 (14B-isomer B): RT = 30.4 min. for (S)-ethyl l-((R)-2-(4- cyanophenyl)-2-hydroxyethyl)piperidine-3-carboxylate.

[00231] Compound 14A-isomer A prepared using this asymmetric method was unambiguously assigned since it was identical to the 14A-isomer A (by ¹H NMR and chiral HPLC retention time) that was prepared above and determined by X-ray crystallography. Synthesis of Example 14 from this material followed the same route as described above.

paper

Regioselective Epoxide Ring Opening for the Stereospecific Scale-Up Synthesis of BMS-960, A Potent and Selective Isoxazole-Containing S1P₁Receptor Agonist

Xiaoping Hou^*† , Huiping Zhang^†, Bang-Chi Chen^†, Zhiwei Guo^‡, Amarjit Singh^‡, Animesh Goswami^‡, John L. Gilmore^†, James E. Sheppeck^†, Alaric J. Dyckman^† , Percy H. Carter^†, and Arvind Mathur^†

^† Discovery Chemistry, Bristol-Myers Squibb, Princeton, New Jersey 08540, United States

^‡ Chemical & Synthetic Development, Bristol-Myers Squibb, New Brunswick, New Jersey 08903, United States

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00366

http://pubs.acs.org/doi/abs/10.1021/acs.oprd.6b00366

*E-mail: xiaoping.hou@bms.com.

This article presents a stereospecific scale-up synthesis of (S)-1-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid (BMS-960), a potent and selective isoxazole-containing S1P₁ receptor agonist. The process highlights an enzymatic reduction of α-bromoketone toward the preparation of (S)-bromo alcohol, a key precursor of (S)-4-(oxiran-2-yl)benzonitrile. A regioselective and stereospecific epoxide ring-opening reaction was also optimized along with improvements to 1,2,4-oxadiazole formation, hydrolysis, and crystallization. The improved process was utilized to synthesize batches of BMS-960 for Ames testing and other toxicological studies.

PAPER

Journal of Medicinal Chemistry (2016), 59(13), 6248-6264.

Discovery and Structure–Activity Relationship (SAR) of a Series of Ethanolamine-Based Direct-Acting Agonists of Sphingosine-1-phosphate (S1P₁)

Abstract

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite that regulates a multitude of physiological processes such as lymphocyte trafficking, cardiac function, vascular development, and inflammation. Because of the ability of S1P₁ receptor agonists to suppress lymphocyte egress, they have great potential as therapeutic agents in a variety of autoimmune diseases. In this article, the discovery of selective, direct acting S1P₁ agonists utilizing an ethanolamine scaffold containing a terminal carboxylic acid is described. Potent S1P₁ agonists such as compounds 18a and 19a which have greater than 1000-fold selectivity over S1P₃ are described. These compounds efficiently reduce blood lymphocyte counts in rats through 24 h after single doses of 1 and 0.3 mpk, respectively. Pharmacodynamic properties of both compounds are discussed. Compound 19a was further studied in two preclinical models of disease, exhibiting good efficacy in both the rat adjuvant arthritis model (AA) and the mouse experimental autoimmune encephalomyelitis model (EAE).

BASE

(S)-1-((S)-2-Hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl) isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic Acid (18a)

(S)-ethyl 1-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylate (36%).

¹H NMR (400 MHz, MeOH-d₃) δ ppm 8.04 (2 H, d, J = 8.13 Hz), 7.55–7.60 (2 H, m), 7.41–7.54 (5 H, m), 4.81 (1 H, ddd, J = 8.35, 4.06, 3.84 Hz), 3.96–4.10 (2 H, m), 2.82–3.08 (1 H, m), 2.67–2.82 (1 H, m), 2.36–2.61 (3 H, m), 2.08–2.33 (2 H, m), 1.73–1.87 (1 H, m, J = 8.54, 8.54, 4.45, 4.17 Hz), 1.32–1.70 (3 H, m), 1.09–1.19 (3 H, m).

MS (M + H)⁺ at m/z 557. HPLC purity: 99%, t_r = 3.36 min (method B).

TFA salt

(S)-1-((S)-2-hydroxy-2-(4-(5-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidine-3-carboxylic acid, TFA salt (18a, 61%) as a white solid.

¹H NMR (400 MHz, MeOH-d₃) δ ppm 8.23 (2 H, d, J = 8.35 Hz), 7.65–7.74 (4 H, m), 7.54–7.65 (3 H, m), 5.29 (1 H, t, J = 7.03 Hz), 4.00 (1 H, br s), 3.43–3.75 (1 H, m), 3.34–3.41 (2 H, m), 2.82–3.24 (2 H, m), 2.26 (1 H, d, J = 11.86 Hz), 1.84–2.14 (2 H, m), 1.52–1.75 (1 H, m).

MS (M + H)⁺ at m/z 529.

HPLC t_r = 3.27 min (method B). HPLC purity: 99.4%, t_r = 8.78 min (method E); 99.0%, t_r = 7.29 min (method F).

HCL SALT

This material was converted to the HCl salt for the following analyses: mp: 219.2 °C. Anal. Calcd for C₂₆H₂₃N₄O₅F₃·HCl: 0.14% water: C, 55.2; H, 4.31; N, 9.87; Cl, 6.25. Found: C, 55.39; H, 4.10; N, 9.88; Cl, 6.34. [α]_D²⁰ + 30.47 (c 0.336, MeOH). HPLC with chiral stationary phase (A linear gradient using CO₂ (solvent A) and IPA with 0.1% DEA (solvent B); t = 0 min, 30% B, t = 10 min, 55% B was employed on a Chiralcel AD-H 250 mm × 4.6 mm ID, 5 μm column; flow rate was 2.0 mL/min): t_r = 5.38 min with >99% ee.

References

//////BMS-960, PRECLINICAL, BMS 960

Cl.O=C(O)[C@H]1CCCN(C1)C[C@@H](O)c2ccc(cc2)c3nc(on3)c5onc(c4ccccc4)c5C(F)(F)F

Plinabulin

• Molecular FormulaC₁₉H₂₀N₄O₂
• Average mass336.388 Da

Tubulin antagonist

Cancer; Febrile neutropenia; Non-small-cell lung cancer

Plinabulin (chemical structure, BPI-2358, formerly NPI-2358) is a small molecule under development by BeyondSpring Pharmaceuticals, and is in a world-wide Phase 3 clinical trial for non-small cell lung cancer. ^[1] Plinabulin blocks the polymerization of tubulin in a unique manner, resulting in multi-factorial effects including an enhanced immune-oncology response, ^[2] activation of the JNK pathway ^[3] and disruption of the tumor blood supply. Plinabulin is being investigated for the reduction of chemotherapy-induced neutropenia ^[4] and for anti-cancer effects in combination with immune checkpoint inhibitors ^{[5] [6]} and in KRAS mutated tumors. ^[7]

Plinabulin is a synthetic analog of diketopiperazine phenylahistin (halimide) discovered from marine and terrestrial Aspergillus sp. Plinabulin is structurally different from colchicine and its combretastatin-like analogs (eg, fosbretabulin) and binds at or near the colchicine binding site on tubulin monomers. Previous studies showed that plinabulin induced vascular endothelial cell tubulin depolymerization and monolayer permeability at low concentrations compared with colchicine and that it induced apoptosis in Jurkat leukemia cells. Studies of plinabulin as a single agent in patients with advanced malignancies (lung, prostate, and colon cancers) showed a favorable pharmacokinetic, pharmacodynamics, and safety profile.

Beyondspring, under license from Nereus (now Triphase, which licensed the program from the Scripps Institute of Oceanography of the University of California San Diego), is developing plinabulin, the lead in the NPI-2350 halimide series of marine Aspergillus-derived, vascular-targeting antimicrotubule agents, for treating cancer, primarily non-small cell lung cancer.

It is thought that a single, universal cellular mechanism controls the regulation of the eukaryotic cell cycle process. See, e.g., Hartwpll, L.H. et al., Science (1989), 246: 629-34. It is also known that when an abnormality arises in the control mechanism of the cell cycle, cancer or an immune disorder may occur. Accordingly, as is also known, antitumor agents and immune suppressors may be among the substances that regulate the cell cycle. Thus, new methods for producing eukaryotic cell cycle inhibitors are needed as antitumor and immune-enhancing compounds, and should be useful in the treatment of human cancer as chemotherapeutic, anti-tumor agents. See, e.g., Roberge, M. et al., Cancer Res. (1994), 54, 6115-21.

Fungi, especially pathogenic fungi and related infections, represent an increasing clinical challenge. Existing antifungal agents are of limited efficacy and toxicity, and the development and/or discovery of strains of pathogenic fungi that are resistant to drags currently available or under development. By way of example, fungi that are pathogenic in humans include among others Candida spp. including C. albicans, C. tropicalis, C. keƒyr, C. krusei and C. galbrata; Aspergillus spp. including A. fumigatus and A. flavus; Cryptococcus neoƒormans; Blastomyces spp. including Blastomyces dermatitidis; Pneumocystis carinii; Coccidioides immitis; Basidiobolus ranarum; Conidiobolus spp.; Histoplasma capsulatum; Rhizopus spp. including R. oryzae and R. microsporus; Cunninghamella spp.; Rhizomucor spp.; Paracoccidioides brasiliensis; Pseudallescheria boydii; Rhinosporidium seeberi; and Sporothrix schenckii (Kwon-Chung, K.J. & Bennett, J.E. 1992 Medical Mycology, Lea and Febiger, Malvern, PA).

Recently, it has been reported that tryprostatins A and B (which are diketopiperazines consisting of proline and isoprenylated tryptophan residues), and five other structurally-related diketopiperazines, inhibited cell cycle progression in the M phase, see Cui, C. et al., 1996 J Antibiotics 49:527-33; Cui, C. et al. 1996 J Antibiotics 49:534-40, and that these compounds also affect the microtubule assembly, see Usui, T. et al. 1998 Biochem J 333:543-48; Kondon, M. et al. 1998 J Antibiotics 51:801-04. Furthermore, natural and synthetic compounds have been reported to inhibit mitosis, thus inhibit the eukaryotic cell cycle, by binding to the colchicine binding-site (CLC-site) on tubulin, which is a macromolecule that consists of two 50 kDa subunits (α- and β-tubulin) and is the major constituent of microtubules. See, e.g., Iwasaki, S., 1993 Med Res Rev 13:183-198; Hamel, E. 1996 Med Res Rev 16:207-31; Weisenberg, R.C. et al., 1969 Biochemistry 7:4466-79. Microtubules are thought to be involved in several essential cell functions, such as axonal transport, cell motility and determination of cell morphology. Therefore, inhibitors of microtubule function may have broad biological activity, and be applicable to medicinal and agrochemical purposes. It is also possible that colchicine (CLC)-site ligands such as CLC, steganacin, see Kupchan, S.M. et al., 1973 J Am Chem Soc 95:1335-36, podophyllotoxin, see Sackett, D.L., 1993 Pharmacol Ther 59:163-228, and combretastatins, see Pettit, G.R. et al., 1995 J Med Chem 38:166-67, may prove to be valuable as eukaryotic cell cycle inhibitors and, thus, may be useful as chemotherapeutic agents.

Although diketopiperazine-type metabolites have been isolated from various fungi as mycotoxins, see Horak R.M. et al., 1981 JCS Chem Comm 1265-67; Ali M. et al., 1898 Toxicology Letters 48:235-41, or as secondary metabolites, see Smedsgaard J. et al., 1996 J Microbiol Meth 25:5-17, little is known about the specific structure of the diketopiperazine-type metabolites or their derivatives and their antitumor activity, particularly in vivo. Not only have these compounds been isolated as mycotoxins, the chemical synthesis of one type of diketopiperazine-type metabolite, phenylahistin, has been described by Hayashi et al. in J. Org. Chem. (2000) 65, page 8402. In the art, one such diketopiperazine-type metabolite derivative, dehydrophenylahistin, has been prepared by enzymatic dehydrogenation of its parent phenylahistin. With the incidences of cancer on the rise, there exists a particular need for chemically producing a class of substantially purified diketopiperazine-type metabolite-derivatives having animal cell-specific proliferation-inhibiting activity and high antitumor activity and selectivity. There is therefore a particular need for an efficient method of synthetically producing substantially purified, and structurally and biologically characterized, diketopiperazine-type metabolite-derivatives.

Also, PCT Publication WO/0153290 (July 26, 2001) describes a non-synthetic method of producing dehydrophenylahistin by exposing phenylahistin or a particular phenylahistin analog to a dehydrogenase obtained from Streptomyces albulus.

Synthesis

PATENT

WO2001053290,

WO 2004054498

PATENT

WO 2005077940

The imidazolecarboxaldehyde may be prepared, for example, according the procedure disclosed in Hayashi et al., 2000 J Organic Chem 65: 8402 as depicted below:

EXAMPLE 2

Synthesis and Physical Characterization of tBu-dehydrophenylahistin Derivatives

[0207] Structural derivatives of dehydrophenylahistin were synthesized according to the following reaction schemes to produce tBu-dehydrophenylahistin. Synthesis by Route

A (see Figure 1) is similar in certain respects to the synthesis of the dehydrophenylahistin synthesized as in Example 1.

Route A:

[0208] N,N’-diacethyl-2,5-piperazinedione 1 was prepared as in Example 1.

1) 1-Acetyl-3-{(Z)-1-[5-tert-butyl-1H-4-imidazolyl]methylidene}]-2,5-piperazinedione (16)

. [0209] To a solution of 5-tert-butylimidazole-4-carboxaldehyde 15 (3.02 g, 19.8. mmol) in DMF (30 mL) was added compound 1 (5.89 g, 29.72 mmol) and the solution was repeatedly evacuated in a short time to remove oxygen and flushed with Ar, followed by the addition of Cs₂CO₃ (9.7 g, 29.72 mmol) and the evacuation-flushing process was repeated again. The resultant mixture was stirred for 5 h at room temperature. After the solvent was removed by evaporation, the residue was dissolved in the mixture of EtOAc and 10% Na₂CO₃, and the organic phase was washed with 10% Na₂CO₃ again and saturated NaCl for three times, dried over Na₂SO₄ and concentrated in vacuo. The residual oil was purified by column chromatography on silica using CHCl₃-MeOH (100:0 to 50:1) as an eluant to give 1.90 g (33 %) of a pale yellow solid 16. ¹H NMR (270 MHz, CDCl₃) δ 12.14 (d, br-s, 1H), 9.22 (br-s, 1H), 7.57 (s, 1H), 7.18, (s, 1H), 4.47 (s, 2H), 2.65 (s, 3H), 1.47 (s, 9H).

2) t-Bu-dehydrophenylahistin

[0210] To a solution of 1-Acetyl-3-{(Z)-1-[5-tert-butyl-1H-4-imidazolyl]methylidene}]-2,5-piperazinedione (16) (11 mg, 0.038 mmol) in DMF (1.0 mL) was added benzaldehyde (19 μL, 0.19 mmol, 5 eq) and the solution was repeatedly evacuated in a short time to remove oxygen and flushed with Ar, followed by the addition of Cs₂CO₃ (43 mg, 0.132 mmol, 3.5 eq) and the evacuation-flushing process was repeated again. The resultant mixture was heated for 2.5 h at 80°C. After the solvent was removed by

evaporation, the residue was dissolved in EtOAc, washed with water for two times and saturated NaCl for three times, dried over Na₂SO₄ and concentrated in vacuo. The resulting residue was dissolved in 90% MeOH aq and applied to reverse-phase HPLC column (YMC-Pack, ODS-AM, 20 × 250 mm) and eluted using a linear gradient from 70 to 74% MeOH in water over 16 min at a flow rate of 12 mL/min, and the desired fraction was collected and concentrated by evaporation to give a 6.4 mg (50%) of yellow colored tert-butyl-dehydrophenylahistin. ¹H NMR (270 MHz, CDCl₃) δ 12.34 br-s, 1H), 9.18 (br-s, 1H), 8.09 (s, 1H), 7.59 (s, 1H), 7.31 – 7.49 (m, 5H), 7.01 s, 2H), 1.46 (s, 9H).

[0211] The dehydrophenylahistin reaction to produce tBu-dehydrophenylahistin is identical to Example 1.

[0212] The total yield of the tBu-dehydrophenylahistin recovered was 16.5%. Route B:

[0213] N,N’-diacethyl-2,5-piperazinedione 1 was prepared as in Example 1.

1) 1-Acetyl-3-[(Z)-benzylidenel]-2,5-piperazinedione (17)

[0214] To a solution of benzaldehyde 4 (0.54 g, 5.05. mmol) in DMF (5 mL) was added compound 1 (2.0 g, 10.1 mmol) and the solution was repeatedly evacuated in a short time to remove oxygen and flushed with Ar, followed by the addition of Cs₂CO₃ (1.65 g, 5.05 mmol) and the evacuation-flushing process was repeated again. The resultant mixture was stirred for 3.5 h at room temperature. After the solvent was removed by evaporation, the residue was dissolved in the mixture of EtOAc and 10% Na₂CO₃, and the organic phase was washed with 10% Na₂CO₃ again and saturated NaCl for three times, dried over Na₂SO₄ and concentrated in vacuo. The residual solid was recrystalized from MeOH-ether to obtain a off-white solid of 17; yield 1.95 g (79%).

2) t-Bu-dehydrophenylahistin

[0215] To a solution of 1-Acetyl-3-[(Z)-benzylidenel]-2,5-piperazinedione (17) (48 mg, 0.197 mmol) in DMF (1.0 mL) was added 5-tert-butylimidazole-4-carboxaldehyde 15 (30 mg, 0.197 mmol) and the solution was repeatedly evacuated in a short time to remove oxygen and flushed with Ar, followed by the addition of Cs₂CO₃ (96 mg, 0.296 mmol) and the evacuation-flushing process was repeated again. The resultant mixture was heated for 14 h at 80°C. After the solvent was removed by evaporation, the residue was dissolved in EtOAc, washed with water for two times and saturated NaCl for three times, dried over Na₂SO₄ and concentrated in vacuo. The resulting residue was dissolved in 90% MeOH aq and applied to reverse-phase HPLC column (YMC-Pack, ODS-AM, 20 x 250 mm) and eluted using a linear gradient from 70 to 74% MeOH in water over 16 min at a flow rate of 12 mL/min, and the desired fraction was collected and concentrated by evaporation to give a 0.8 mg (1.2%) of yellow colored tert-butyl-dehydrophenylahistin.

[0216] The total yield of the tBu-dehydrophenylahistin recovered was 0.9%.

[0217] The HPLC profile of the crude synthetic tBu-dehyrophenylahistin from Route A and from Route B is depicted in Figure 4.

[0218] Two other tBu-dehydrophenylahistin derivatives were synthesized according to the method of Route A. In the synthesis of the additional tBu-dehydrophenylahistin derivatives, modifications to the benzaldehyde compound 4 were made.

[0219] Figure 4 illustrates the similarities of the HPLC profiles (Column: YMC-Pack ODS-AM (20 × 250mm); Gradient: 65% to 75% in a methanol-water system for 20 min, then 10 min in a 100% methanol system; Flow rate: 12mL/min; O.D. 230 nm) from the synthesized dehydrophenylahistin of Example 1 (Fig 2) and the above exemplified tBu-dehydrophenylahistin compound produced by Route A.

[0220] The sequence of introduction of the aldehydes is a relevant to the yield and is therefore aspect of the synthesis. An analogue of dehydrophenylahistin was synthesized, as a confrol or model, wherein the dimethylallyl group was changed to the tert-butyl group with a similar steric hindrance at the 5-position of the imidazole ring.

[0221] The synthesis of this “tert-butyl (tBu)-dehydrophenylahistin” using “Route A” was as shown above: Particularly, the sequence of infroduction of the aldehyde exactly follows the dehydrophenylahistin synthesis, and exhibited a total yield of 16.5% tBu-dehydrophenylahistin. This yield was similar to that of dehydrophenylahistin (20%). Using “Route B”, where the sequence of introduction of the aldehydes is opposite that of Route “A” for the dehydrophenylahistin synthesis, only a trace amount of the desired tBu-dehydroPLH was obtained with a total yield of 0.9%, although in the introduction of first benzaldehyde 4 gave a 76% yield of the intermediate compound 17. This result indicated that it may be difficult to introduce the highly bulky imidazole-4-carboxaldehydes 15 with a substituting group having a quaternary-carbon on the adjacent 5-position at the imidazole ring into the intermediate compound 17, suggesting that the sequence for introduction of aldehydes is an important aspect for obtaining a high yield of dehydrophenylahistin or an analog of dehydrophenylahistin employing the synthesis disclosed herein:

[0222] From the HPLC analysis of the final crude products, as shown in Figure 4, a very high content of tBu-dehydrophenylahistin and small amount of by-product formations were observed in the crude sample of Route A (left). However, a relatively smaller amount of the desired tBu-dehydrophenylahistin and several other by-products were observed in the sample obtained using Route B (right).

Synthesis oƒ 3-Z-Benzylidene-6-(5″-tert-butyl-1H-imidazol-4″-Z-ylmethylene)-piperazine-2,5-dione (2)

Reagents: g) SO₂Cl₂; h) H₂NCHO, H₂O; I)LiAlH₄; j) MnO₂; k) 1,4-diacetyl-piperazine-2,5-dione, Cs₂CO₃; 1) benzaldehyde, Cs₂CO₃

2-Chloro-4,4-dimethyl-3-oxo-pentanoic acid ethyl ester

[0280] Sulfuryl chloride (14.0 ml, 0.17 mol) was added to a cooled (0°) solution of ethyl pivaloylacetate (27.17 g, 0.16 mol) in chloroform (100 ml). The resulting mixture was allowed to warm to room temperature and was stirred for 30 min, after which it was heated under reflux for 2.5 h. After cooling to room temperature, the reaction mixture was diluted with chloroform, then washed with sodium bicarbonate, water then brine.

[0281] The organic phase was dried and evaporated to afford, as a clear oil, 2-chloro-4,4-dimethyl-3-oxo-pentanoic acid ethyl ester (33.1 g, 102%). (Durant et al., “Aminoalkylimidazoles and Process for their Production.” Patent No. GB1341375 (Great Britain, 1973)).

[0282] HPLC (214nm) t_R = 8.80 (92.9%) min.

[0283] ¹H NMR (400 MHz, CDCl₃) δ 1.27 (s, 9H); 1.29 (t, J= 7.2 Hz, 3H); 4.27

(q, J= 7.2 Hz, 2H); 5.22 (s, 1H).

[0284] ¹³C NMR (100 MHz, CDCl₃) δ 13.8, 26.3, 45.1, 54.5, 62.9, 165.1, 203.6.

5-tert-Butyl-3H-imidazole-4-carboxylic acid ethyl ester

[0285] A solution of 2-chloro-4,4-dimethyl-3-oxo-pentanoic acid ethyl ester (25.0 g, 0.12 mol) in formamide (47.5 ml) and water (2.5 ml) was shaken, then dispensed into 15 x 8 ml vials. All vials were sealed and then heated at 150° for 3.5 h. The vials were allowed to cool to room temperature, then water (20 ml) was added and the mixture was exhaustively extracted with chloroform. The chloroform was removed to give a concentrated formamide solution (22.2 g) which was added to a flash silica column (6 cm diameter, 12 cm height) packed in 1% MeOH/1% Et₃N in chloroform. Elution of the column with 2.5 L of this mixture followed by 1 L of 2% MeOH/1% Et₃N in chloroform gave, in the early fractions, a product suspected of being 5-tert-butyl-oxazole-4-carboxylic acid ethyl ester (6.3 g, 26%).

[0286] HPLC (214nm) t_R = 8.77 min.

[0287] ¹H NMR (400 MHz, CDCl₃) δ 1.41 (t, J= 7.2 Hz, 3H); 1.43 (s, 9H); 4.40

(q, J= 7.2 Hz, 2H); 7.81 (s, 1H).

[0288] ¹³C NMR (100 MHz, CDCl₃) δ 14.1, 28.8, 32.5, 61.3, 136.9, 149.9, 156.4,

158.3.

[0289] ESMS m/z 198.3 [M+H]⁺, 239.3 [M+CH₄CN]⁺.

[0290] LC/MS t_R = 7.97 (198.1 [M+H]⁺) min.

[0291] Recovered from later fractions was 5-tert-butyl-3H-imidazole-4-carboxylic acid ethyl ester (6.20 g, 26%). (Durant et al., “Aminoalkylimidazoles and Process for their Production.” Patent No. GB 1341375 (Great Britain, 1973)).

[0292] HPLC (214nm) t_R = 5.41 (93.7%) min.

[0293] ¹H NMR (400 MHz, CDCl₃) δ 1.38 (t, J = 7.0 Hz, 3H); 1.47 (s, 9H); 4.36

(q, J= 7.2 Hz, 2H); 7.54 (s, 1H).

[0294] ¹³C NMR (100 MHz, CDCl₃) δ 13 7, 28.8, 32.0, 59.8, 124.2, 133.3, 149.2,

162.6.

[0295] ESMS m/z 197.3 [M+H]⁺, 238.3 [M+CH₄CN]⁺.

[0296] Further elution of the column with 1L of 5% MeOh/1% Et₃N gave a compound suspected of being 5-tert-butyl-3H-imidazole-4-carboxylic acid (0.50 g, 2%).

[0297] HPLC (245nm) t_R = 4.68 (83.1%) min.

[0298] ¹H NMR (400 MHz, CD₃OD) δ 1.36 (s, 9H); 7.69 (s, 1H).

[0299] ¹H NMR (400 MHz, CDCl₃) δ 1.37 (s, 9H); 7.74 (s, 1H).

[0300] ¹H NMR (400 MHz, CD₃SO) δ 1.28 (s, 9H); 7.68 (s, 1H).

[0301] ESMS m/z 169.2 [M+H]⁺, 210.4 [M+CH₄CN]⁺.

(5-tert-Butyl-3H-imidazol-4-yl)-methanol

[0302] A solution of 5-tert-butyl-3-imidazole-4-carboxylic acid ethyl ester (3.30 g, 16.8 mmol) in THF (60 ml) was added dropwise to a suspension of lithium aluminium hydride (95% suspension, 0.89 g, 22.2 mmol) in THF (40 ml) and the mixture was stirred at room temperature for 3 h. Water was added until the evolution of gas ceased, the mixture was stirred for 10 min, then was filtered through a sintered funnel. The precipitate was washed with THF, then with methanol, the filtrate and washings were combined and evaporated. The residue was freeze-dried overnight to afford, as a white solid (5-tert-butyl- 3H-imidazol-4-yl)-methanol (2.71 g, 105%). (Durant et al., “Aminoalkylimidazoles and Process for their Production.” Patent No. GB1341375 (Great Britain, 1973)).

[0303] HPLC (240nm) t_R = 3.70 (67.4%) min.

[0304] ¹H NMR (400 MHz, CD₃OD) δ 1 36 (s, 9H). 4 62 (s, 2H); 7.43 (s, 1H).

[0305] ¹³C NMR (100 MHz, CD₃OD) δ 31.1, 33.0, 57.9, 131.4, 133.9, 140.8.

[0306] LC/MS t_R = 3.41 (155.2 [M+H]⁺) min.

[0307] This material was used without further purification.

5-tert-Butyl-3H-imidazole-4-carbaldehyde

[0308] Manganese dioxide (30 g, 0.35 mol) was added to a heterogeneous solution of (5-tert-butyl-3H-imidazol-4-yl)-methanol (4.97 g, 0.03 mol) in acetone (700 ml) and the resulting mixture was stirred at room temperature for 4 h. The mixture was filtered through a pad of Celite and the pad was washed with acetone. The filfrate and washings were combined and evaporated. The residue was triturated with ether to afford, as a colorless solid, 5-tert-butyl-3H-imidazole-4-carbaldehyde (2.50 g, 51%). (Hayashi, Personal Communication (2000)).

[0309] HPLC (240nm) t_R = 3.71 (89.3%) min.

[0310] ¹H NMR (400 MHz, CDCl₃) δ 1.48 (s, 9H); 7.67 (s, 1H); 10.06 (s, 1H).

[0311] LC/MS t_R = 3.38 (153.2 [M+H]⁺) min.

[0312] Evaporation of the filtrate from the trituration gave additional 5-tert-butyl-3H-imidazole-4-carbaldehyde (1.88 g, 38%).

1-Acetyl-3-(5′-tert-butyl-1H-imdazol-4′-Z-ylmethylene)-piperazine-2,5-dione

[0313] To a solution of 5-tert-butyl-3H-imidazole-4-carbaldehyde (2.50 g, 164.4 mmol) in DMF (50 ml) was added 1,4-diacetyl-piperazine-2,5-dione (6.50 g, 32.8 mmol) and the solution was evacuated, then flushed with argon. The evacuation-flushing process was repeated a further two times, then cesium carbonate (5.35 g, 16.4 mmol) was added. The evacuation-flushing process was repeated a further three times, then the resultant mixture was stirred at room temperature for 5 h. The reaction mixture was partially evaporated (heat and high vacuum) until a small volume remained and the resultant solution was added dropwise to water (100 ml). The yellow precipitate was collected, then freeze-dried to afford 1-acetyl-3-(5′-tert-butyl-1Η-imidazol-4′-Z-ylmethylene)-piperazine-2,5-dione (2.24 g, 47%). (Hayashi, Personal Communication (2000)).

[0314] HPLC (214nm) t_R = 5.54 (94.4%) min.

[0315] ¹H NMR (400 MHz, CDCl₃) δ 1.47 (s, 9H); 2.65 (s, 3H), 4.47 (s, 2H);

7.19 (s, 1H); 7.57 (s, 1H), 9.26 (s, 1H), 12.14 (s, 1H).

[0316] ¹³C NMR (100 MHz, CDCI₃+CD₃OD) δ 27.3, 30.8, 32.1, 46.5, 110.0,

123.2, 131.4, 133.2, 141.7, 160.7, 162.8, 173.0

[0317] LC/MS t_R = 5.16 (291.2 [M+H]⁺, 581.6 [2M+H]⁺) min.