NEW PATENT, PONESIMOD, CRYSTAL PHARMATECH, WO 2017107972

NEW PATENT, PONESIMOD,  CRYSTAL PHARMATECH, WO 2017107972

Novel crystalline forms I, II and III of ponesimod . Useful as a selective sphingosine-1-phosphate receptor-1 (S1P1) receptor agonist, for the treatment of psoriasis. Appears to be first filing from Crystal Pharmatech claiming ponesimod. Johnson & Johnson , following its acquisition of Actelion , is developing ponesimod (phase III clinical trial), a S1P1 agonist, for the treatment of autoimmune disorders. 

Applicants:	CRYSTAL PHARMATECH CO., LTD. [CN/CN]; B4-101, Biobay, 218 Xinghu Street, Suzhou Industrial Park Suzhou, Jiangsu 215123 (CN)
Inventors:	CHEN, Minhua; (CN). ZHANG, Yanfeng; (CN). LI, Jiaoyang; (CN). ZHANG, Xiaoyu; (CN)

Most of the family members of the product case ( WO2005054215 ) of ponesimod expire in European countries until November, 2023 and in the US by December, 2024 with US154 extension.

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2017107972&redirectedID=true

Disclosed are crystalline forms 1, 2, and 3 of a selective S1P1 receptor agonist, namely Ponesimod, and a method for preparing the same. An X-ray powder diffraction pattern of the crystalline form 1 has characteristic peaks at 2 theta values of 18.1° ± 0.2°, 14.6° ± 0.2°, and 11.3° ± 0.2°. An X-ray powder diffraction pattern of the crystalline form 2 has characteristic peaks at 2 theta values of 3.8° ± 0.2°, 10.8° ± 0.2°, and 6.1° ± 0.2°. An X-ray powder diffraction pattern of the crystalline form 3 has characteristic peaks at 2 theta values of 12.2° ± 0.2°, 6.2° ± 0.2°, and 5.6° ± 0.2°. Compared with existing crystalline forms, the present invention has better stability and a greatly increased solubility, and is more suitable for development of a pharmaceutical preparation containing Ponesimod

Ponesimod (compound of formula I) is a selective S1P1 receptor antagonist developed by Actelion. The drug was used to treat moderate to severe chronic plaque psoriasis in the two medium-term trial was successful, and will carry out the treatment of psoriasis in 3 clinical trials.

The present invention discloses a process for the preparation of a compound of formula I, which is disclosed in patent CN 102177144B, which is an amorphous form prepared by the process of CN100567275C, and discloses a process for the preparation of a compound of formula I, crystalline form C, crystalline form III, Type II. The results show that the crystallinity of crystalline form III is poor and it is converted to crystalline form II at room temperature. The crystalline form II is difficult to repeat and prepare a certain amount of propionic acid. The thermodynamics stability of crystalline form A is inferior to that of crystal form C. In contrast, For the crystal form suitable for the development of the drug, the solubility of the crystalline form C is not ideal.

Example 1

[0060]

Preparation of Ponesimod Form 1:

[0061]

48.1 mg of Ponesimod was added to 0.40 mL of 1,4-dioxane and the filtrate was filtered. To the solution was stirred at room temperature, 1.20 mL of n-heptane was added dropwise to precipitate the crystals and stirred overnight. The supernatant was filtered off by centrifugation Liquid to obtain Ponesimod crystal form 1.

Follow "'2014' Suzhou International Elite Entrepreneurship Week" with interest Over 88 billion venture capital investment helps your pioneering dreams come true



Since 2009, there have been 1267 overseas high-level talent projects settled in Suzhou through International Elite Entrepreneurship Week and 54 talents have been introduced and fostered for the national "Thousand Talents Plan". Among these 53 talents, Dr. Chen Minhua, the founder of Suzhou Crystal Pharmatech Co., Ltd., was deeply impressed by thoughtful services in Suzhou for innovative pioneering talents when he recalled the development in Suzhou. "Investment and financing services are placed with particular importance. Everything is thoroughly considered for fear that enterprise
In 2010, Chen Minhua quitted his job in a well-known pharmaceutical company in the United States and returned with his core 4-people R&D team. He founded Crystal Pharmatech Co., Ltd. in Suzhou Biobay through the Entrepreneurship Week. Till 2013, Crystal Pharmatech has made profits year by year. The yearly output value in 2013 reached 18 million Yuan, while the profits reached as high as 4 million Yuan. His clients involve half of top 20 pharmaceutical companies globally. Chen Minhua longs to fill the vacancy of drug crystals in China and take the lead in the international drug crystal research. Chen Minhua introduced that government service is an integral part to his growth. "Since it was settled down, Suzhou public sector organized several investment and financing activities and offered training and services in various aspects like the mode of financing, finance docking and enterprise strategic investment, which laid a solid foundation for Crystal Pharmatech's capital expansion", said by Chen Minhua.


To help high-level talents solve financial difficulty, Suzhou lays stress on the docking of science & technology and finance. The person in charge of the Municipal Science and Technology Bureau said that Suzhou guides and integrates social capital for equity investment of hi-tech enterprises at the start-up stage via the guiding funds set up by the government and follow-up investment, etc, thus evolving the venture capital investment cluster based on Shahu Equity Investment Center. After the national "Thousand Talents Plan" venture capital investment center was set up, pioneering talents and venture capital are further converging here. As of the end of 2013, there are 270 effective organizations engaged in various venture capital investment in Suzhou that manage the funds in excess of 88 billion Yuan. 30 million Yuan will be appropriated from the municipal science and technology fund budget for the newly established FOF of Angel Investment this year, so as to take avail of social capital for the development of small and medium-sized hi-tech enterprises.


Meanwhile, Suzhou sets up the special compensation fund against credit risks and offers "Kedaitong" with "low threshold and low interest rate", so as to solve financial difficulty of small and medium-sized hi-tech enterprises and create favorable financing environment for the pioneering work of talents and corporate development. At present, the fund of credit risk pool has reached 500 million Yuan and "Kedaitong" loans of 8.52 billion Yuan have been granted for 1023 small and medium-sized hi-tech enterprises. Particularly, 120 pioneering enterprises that feature independent intellectual property, high content of technology and light assets were backed up with 1.314 billion Yuan, the special risk compensation fund of "Kedaitong", thus vigorously supporting innovation and pioneering work of leading talents in the science and technology community in Suzhou.


Reporter Qian Yi
Quoted from Suzhou Daily on July 6, 2014

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Imigliptin dihydrochloride, Xuanzhu Pharma Co Ltd, NEW PATENT, WO 2017107945

Imigliptin dihydrochloride, Xuanzhu Pharma Co Ltd, NEW PATENT, WO 2017107945

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2017107945&redirectedID=true

Applicants:	XUANZHU PHARMA CO.,LTD. [CN/CN]; 2518, Tianchen Street, National High-tech Development Zone Jinan, Shandong 250101 (CN)
Inventors:	SHU, Chutian; (CN). WANG, Zhenhua; (CN)

The present invention relates to a crystalline form of benzoate of a dipeptidyl peptidase-IV inhibitor, a method for preparing the same, a pharmaceutical composition,and a use thereof. Specifically, the present invention relates to a crystalline form of benzoate of a compound used as a dipeptidyl peptidase-IV inhibitor and represented by formula (1), namely (R)-2-((7-(3-aminopiperidine-1-yl)-3,5-dimethyl-2-oxo-2,3-dihydro-1H-imidazo(4,5-b)pyridine-1-yl)methyl)benzonitrile, a method for preparing the same, a pharmaceutical composition, and a use thereof.

Novel crystalline form I of imigliptin dihydrochloride as dipeptidyl peptidase IV inhibitor (DPP-IV) for the treatment of and/or prevention of non-insulin dependent diabetes, hyperglycemia and hyperlipidemia. In June 2017, KBP Biosciences and Xuanzhu Pharma , subsidiaries of Sihuan Pharmaceutical , are developing an imigliptin dihydrochloride (phase II clinical trial), a DPP-IV inhibitor and a hypoglycemic agent,, for the treatment of type II diabetes. Follows on from WO2013007167 , claiming similar composition.

Dipeptidyl peptidase-IV (DPP-IV) inhibitor is a new generation of oral type 2 diabetes treatment drugs, by enhancing the role of intestinal insulin to play a role, non-insulin therapy drugs. Compared with conventional drugs for the treatment of diabetes, DPP-IV inhibitors do not have weight gain and edema and other adverse reactions.

 

The compound (R) -2 - ((7- (3-aminopiperidin-1-yl) -3,5-dimethyl-2-oxo-2,3-dihydro- 1H-imidazo [4,5-b] pyridin-1-yl) methyl) benzonitrile (described in the specification as a compound of formula (1), as described in patent application PCT / CN2011 / 000068) Inhibitors of compounds, DPP-IV has a strong inhibitory effect and a high selectivity.

 

 

The study of crystal form plays an important role in drug development process. Application No. PCT / CN2012 / 078294 discloses the dihydrochloride crystal form I of the compound of formula (1), in order to meet the requirements of formulation, production and transportation , We further studied the crystal form of the compound of formula (1) in order to find a better crystal form.

Example 1 Preparation of benzoate form I of compound of formula (1)

 

 

40 g (0.1 mol) of the compound of the formula (1) was added to a 2 L round bottom flask, suspended in 1428 mL of acetonitrile, and the temperature was raised to 60 ° C. The free solution was dissolved, 14.3 g (0.1 mol) of benzoic acid was added, The precipitate was dried at 60 ° C for 1 hour and then allowed to stand at room temperature. The filter cake was dried in vacuo at 40 ° C for 10 hours and weighed 51.6 g in 97.4% yield. By XRPD test, for the benzoate crystal type Ⅰ.

////////////////Imigliptin dihydrochloride, Xuanzhu Pharma Co Ltd, NEW PATENT, WO 2017107945

CFDA Granted Approval of Phase II/III Clinical Trials for Imigliptin Hydrochloride

2016-08-04 15:25:37 Author：admin

        Phase II/ III Clinical Trials of Imigliptin Hydrochloride (KBP-3853) have been approved by CFDA; the Clinical Approval Numbers are 2016L05997 and 2016L06137.

 

        As we know, in Phase I study both single and multiple doses of Imigliptin Hydrochloride were safe and well tolerated in healthy volunteers and in Type 2 diabetes patients. Imigliptin Hydrochloride demonstrated good pharmacokinetic (PK) characteristics and exhibited dose-proportional plasma exposure. The potent and long duration inhibition of DPP-4 was validated in the PK/PD study. The results of Phase I study of Imigliptin Hydrochloride warranted its long-term safety and efficacy studies in Phase II/ III.

 

        Currently, the Imigliptin Hydrochloride team has completed the production of clinical trial drug product, as well as finalized the clinical protocols and the study sites. Phase II clinical trial of Imigliptin Hydrochloride will begin in the near future.

 

       The approval of Imigliptin Hydrochloride for the phase II/ III clinical trials represents another milestone in the SiHuan/ XuanZhu’s new drug discovery history. We enter into a new clinical stage of the development process, and we have many works remaining before us. It is still an urgent task for us to accelerate the clinical development, and to launch the drug product in the China market as soon as possible.

QUILSECONAZOLE, VT 1129, New Patent, WO, 2017049080, Viamet

VT 1129 BENZENE SULFONATE

CAS 1809323-18-9

VT 1129

1340593-70-5 CAS

MF C22 H14 F7 N5 O2, MW 513.37

2-Pyridineethanol, α-(2,4-difluorophenyl)-β,β-difluoro-α-(1H-tetrazol-1-ylmethyl)-5-[4-(trifluoromethoxy)phenyl]-, (αR)-

R ISOMER

ROTATION +

QUILSECONAZOLE, VT-1129

Viamet, in collaboration with Therapeutics for Rare and Neglected diseases, is investigating quilseconazole benzenesulfonate (VT-1129), a small-molecule lanosterol demethylase (CYP51) inhibitor, developed using the company's Metallophile technology, for treating fungal infections, including Cryptococcus neoformans meningitis.

WO-2017049080

  

////////////QUILSECONAZOLE, VT-1129, New Patent, WO, 2017049080, Viamet

New Patent, (S)-pregabalin, WO 2017019791, Teva

Synthesis of (S)-pregabalin, Teva

WO-2017019791

TEVA PHARMACEUTICALS INTERNATIONAL GMBH [CH/CH]; Schusselstrasse 12 8645 Jona (CH) (For All Designated States Except US).
JANAGANI, Satyanarayana [US/US]; (US) (US only)

Improved process for preparing (S)-pregabalin, useful for treating pain, seizures, convulsions and anxiety. Also claims novel intermediates of (S)-pregabalin and their preparation method.

Pregabalin, a GABA alpha-2-delta subunit agonist, had been developed and launched by Pfizer.

Teva received a FDA approval for its generic pregabalin capsules (25, 50, 75, 100, 150, 200, 225 and 300 mg).

S)-Pregabalin, (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid, a compound having the chemical structure,

is also known as pregabalin, γ-amino butyric acid or (S)-3-isobutyl GABA. (S)-Pregabalin, marketed under the name LYRICA®, has been found to activate GAD (L-glutamic acid decarboxylase). (S)-Pregabalin has a dose dependent protective effect on seizure, and is a CNS-active compound. (S)-Pregabalin is useful in anticonvulsant therapy, due to its activation of GAD, promoting the production of GABA, one of the brain's major inhibitory neurotransmitters, which is released at 30 percent of the brains synapses. (S)-Pregabalin has analgesic, anticonvulsant, and anxiolytic activity.

Several processes for the synthesis of (S)-Pregabalin are known. For example, U.S. Patent No. 5,599,973 ("'973 patent") discloses the preparation of (S)-Pregabalin using a stoichiometric amount of (4R,5S)-(+) 4-methyl-5-phenyl-2-oxazolidinone as a chiral auxiliary that may be recycled. See, e.g., '973 patent, col. 14, 1. 29 to col. 18, 1. 23 (example 1). In general, however, the route disclosed in the '973 patent is of limited use on an industrial scale, principally due to the low temperature required for the reaction (e.g., -78°C), the use of pyrophoric reagent (e.g., butyl lithium), and a low overall yield (e.g. , 59%, 65%).

U.S. Publication No. 2003/0212290 ("'290 publication") discloses the synthesis of (S)-Pregabalin by an asymmetric hydrogenation of a cyano-substituted olefin of formula 7, to produce a cyano precursor of (S)-3-(aminomethyl)-5-methyl hexanoic acid of formula 8, which i btain (S)-Pregabalin, as described in the following scheme.

[(R,R)-MeD PHOS]Rh(COD)+BF4-

However, the disclosed method requires the use of carbon monoxide under high pressure, raising serious problems in adapting this process for production scale.

Another process is disclosed by G.M. Sammis, et al, J. Am. Chem. Soc , 125(15): 4442-43 (2003), in which an aluminum salen catalyst is used in the conjugate addition of hydrogen cyanide to a, β-unsaturated imides.

Pregabalin

This process is also not practical for large scale production due to the use of highly poisonous reagents. In addition, the last reduction step requires high hydrogen pressure, which only adds to the difficulties required for adapting this process for use on an industrial scale.

International Publication WO 2006/110783 reports several processes for preparing (S)-Pregabalin via the following intermediate and its analogues.

R^OC "COOR2

wherein Ri and R2 are independently H, a straight or branched Ci-10 alkyl, C6-10 aryl, or C3-6 allyl.

U.S. Publication Nos. 2007/0191636 and 2007/0197827 also disclose processes for preparing (S)-Pregabalin.

Thus, there is a need in the art for additional process for the preparation of (S)-Pregabalin that provide (S)-Pregabalin in high quality and high yield, and that can be adapted to large (industrial) scale production.

EXAMPLES

Example 1: Preparation of (3S)-5-methyl-3-(2-oxo-2{[(lS)-l-phenylethyllamino} ethyl) hexanoic acid (III, wherein Ar = phenyl and R = methyl) with recycling of compound (Ilia)

A. 3-isobutylglutaric acid (700g) and acetic anhydride (420g) were heated to 130-140°C and maintained for about 3 hrs. At the end of the reaction, the reaction mixture was cooled to 70-80°C and acetic acid and acetic anhydride were distilled off under vacuum. Toluene (700 mL) was added to the reaction mixture and further evaporated=for 1.5-2 hrs at 90-95°C. Another 700mL of toluene were added and the resulting 4-isobutylglutaric anhydride (IBG anhydride) solution was cooled to 25-30°C.

B. A different reactor was charged with toluene (4L), S-phenylethylamine (1.05 mol equivalent) and 4-dimethylaminopyridine (DMAP) (4.5g) and the mixture was cooled to

-25 to -15°C. The IBG anhydride solution was added and stirred at -25 to -15°C for 2-3 hrs. The mixture was heated to 25-30°C, 180 mL of aq. HC1 (30%) and water (180 mL) were added and the mixture was heated to 70-75°C. The phases were separated and the organic phase was cooled to 15-30°C and stirred for 2-2.5 hrs. The mixture was filtered and washed twice with toluene (2 vol.).

C. The toluene mother liquor, contained 226 g of the compound of formula Ilia (Ar = phenyl and R = methyl) (ee 76.7 %). The toluene was distilled off to 3 vol and 136 g acetylchloride were added. The mixture was heated to 78-82°C and stirred for 5-6 hrs. At the end of the reaction time, 1130 mL water was added at 50-60°C and the phases were separated. 47.39 g NaOH in 474 mL of water were added to the organic phase and the reaction mixture was heated to 78-82°C and stirred for 8-10 hrs. Then, the reaction mixture was cooled to 25-30°C and the pH was adjusted to 1-3 with 30% HC1. Toluene (8 vol.) was added to the mixture and the phases were separated at 80°C. The organic phase was cooled to 25-30°C and filtered. The filtrate was washed with toluene (2 vol.) and re-crystallized from toluene. Yield 44.94%, purity 97.5%, ee 99.88%.

Example 2: Preparation of (3S)-5-methyl-3-(2-oxo-2{[(lS)-l-phenylethyllamino} ethyl) hexanoic acid

A three-necked flask equipped with an addition funnel, thermometer pocket, drying tube and a mechanical stirrer, was charged with toluene (400 ml), (S)-(-)-phenylethylamine (142.35 g,1.1764 mole), and 4-dimethylaminopyridine (0.7176 g, 0.0059 mole). The mixture was cooled to a temperature of -10°C to -15°C, followed by addition of a solution of 3- isobutyl glutaric anhydride (100 g, 0.59 mole) [e.g. obtained in accordance with the process disclosed Drugs of the Future, 24 (8), 862-870 (1999) or according to Example 1 step (A) above] in toluene (100 ml), over a period of 45-60 minutes, and stirring for additional 1.5-2 hours, at a temperature of -10°C to -15°C. The mixture was then extracted with 10% aqueous solution of NaOH (500 ml), and the aqueous phase was washed with toluene (1x250 ml). The pH of the aqueous phase was adjusted to 2-2.5 by adding a solution of hydrochloric acid (1-12N). The aqueous phase was further extracted with toluene (lx 800 ml) at a temperature of 70-80°C. The toluene layer was washed with 10% sodium chloride solution {700ml) at a temperature of 70-80°C followed by crystallization to get 125 g (73.0% yield) of a white solid of (3S)-5-methyl-3-(2-oxo-2-{[(l S)-l-phenylethyl]amino}ethyl) hexanoic acid with an optical purity of 99.75 %, as measured by chiral HPLC.

The toluene mother liquor obtained from the crystallization, which contains a mixture of diastereomers [i.e. compound (Ilia) and (III) wherein Ar = phenyl and R = methyl) is then further processed in accordance with Example 1, step C, in order to convert the compound of formula (Ilia) to (III).

Example 3; Preparation of (3S)-5-methyl-3-(2-oxo-2{[(l S)-l-phenylethyllamino} ethyl) hexanoic acid

Desired major

To a cooled (0 °C) solution of 4-Isobutylglutaric anhydride (0.1 moles) in toluene is added (lS)-l-phenylethanamine (0.1 moles) slowly during 30 minutes and the mixture is warmed to 70 °C, washed with dilute HC1 followed by brine and cooled to ambient temperature during several hours. The precipitate is filtered, washed with toluene and vacuum dried until constant weight to yield (3S)-5-methyl-3-[2-oxo-2-[[(lS)-l-phenylethyl] amino] ethyl]hexanoic acid. Diastereomeric purity by HPLC = 99.5%.

The toluene mother liquor obtained from the precipitation, which contains a mixture of diastereomers [i.e. compound (Ilia) and (III) wherein Ar = phenyl and R = methyl) is then further processed in accordance with Example 1, step C, in order to convert the compound of formula (Ilia) to (III).

Example 4: Preparation of {(S)-4-methyl-2-[((S)-l-phenylethylcarbamoyl)-methyllpentvUcarbamic acid methyl ester

A three-necked flask equipped with an addition funnel, thermometer pocket, drying tube and a mechanical stirrer, was charged with acetone (25 ml), (3S)-5-methyl-3-(2-oxo-2{[(l S)-l-phenylethyl]amino} ethyl) hexanoic acid (5 g, 0.0172 mole), and with

triethylamine (2.17g, 0.0215 mole), and cooled to -10° to -20°C followed by addition of solution of ethyl chloroformate (2.05 g, 0.0189 mole in 5 ml acetone). The mixture was stirred for 1 hour at a temperature of -10° to -20°C, followed by addition of solution of sodium azide (2.8g, 0.0429 mole in water). The resulted slurry was maintained for 1 hour at -10° to -20°C, quenched over ice water followed by extracting the mass with sufficient amount of toluene. The toluene layer was slowly added over a refluxing mixture of toluene and methyl alcohol, followed by stirring for 2 to 4 hours. The stripping off the solvent results in 4.95 g (89.7% yield) of {(S)-4-methyl-2-[((S)-l-phenylethylcarbamoyl)-methyl]pentylcarbamic acid methyl ester (120) with a purity of 97.4% area, as measured by HPLC.

Example 5: Preparation of (S)-Pregabalin

A 0.2 1 reactor was loaded with 70% sulfuric acid (200 g) containing compound 26 (10 g, 0.031 mole), and was heated to 115-120°C for 5-10 hours, and then cooled to room temperature, i.e., about 20° to about 25°C. An aqueous 40% sodium hydroxide solution was added in an amount sufficient to provide a pH of 1. The solution was then extracted with 35 ml of iso-butanol, the organic layer was separated, and Β¾Ν was added in an amount sufficient to provide a pH of 4. The (S)-Pregabalin was precipitated, filtered, and washed with 10 ml of iso-butanol. After drying at 55°C under vacuum, (S)-Pregabalin was obtained as white crystals in a 40.4% yield. Purity: 99.95% area by HPLC.

Example 6: Preparation of (S)-Pregabalin

A flask was loaded with 47% HBr (12 ml), water (6 ml), and compound 26 (6 g), and then was heated to reflux for 3 hours. The solution was cooled to room temperature, and water (12 ml) was added. An aqueous 47% sodium hydroxide solution was added to obtain

pH of 3. The solution was then extracted twice with isobutanol (15 ml), the combined organic layers were evaporated and fresh isobutanol was added (15 ml). B¾N (3.8 g) was added. The mixture was cooled to 2°C for 1 hour, then (S)-Pregabalin was filtered, and washed with of iso-butanol (3 ml). After drying at 55°C under vacuum, (S)-Pregabalin was obtained as white crystals in a 90% yield.

Example 7: Conversion of the Compound of Formula 4 to (S)-Pregabalin: Example 14 of International Publication No. WO 2007/035890

A 0.2 1 reactor was loaded with 70% sulfuric acid (200 g) containing compound 26 (10 g, 0.031 mole), and was heated to 115-120°C for 5-10 hours, and then cooled to room temperature, i.e., about 20° to about 25°C. An aqueous 40% sodium hydroxide solution was added in an amount sufficient to provide a pH of 1. The solution was then extracted with 35 ml of iso-butanol, the organic layer was separated, and Bu3N was added in an amount sufficient to provide a pH of 4. The (S) Pregabalin was precipitated, filtered, and washed with 10 ml of iso-butanol. After drying at 55°C under vacuum, (S)-Pregabalin was obtained as white crystals in a 40.4% yield. Purity: 99.95% area by HPLC.

Compound 26 has the following chemical structure:

wherein Ar is a C6-1o aromatic group, and R is a straight or branched C1-4 alkyl, ester or carboxylic acid.

Example 8: Conversion of the Compound of Formula 4 to (S)-Pregabalin: Example 16 of International Publication No. WO 2007/035890

A flask was loaded with 47% HBr (12 ml), water (6 ml), and compound 26 (6 g), and then was heated to reflux for 3 hours. The solution was cooled to room temperature, and water (12 ml) was added. An aqueous 47% sodium hydroxide solution was added to obtain pH of 3. The solution was then extracted twice with isobutanol (15 ml), the combined organic layers were evaporated and fresh isobutanol was added (15 ml). Bu3N (3.8 g) was added. The mixture was cooled to 2°C for 1 hour, then (S)-Pregabalin was filtered, and washed with of iso-butanol (3 ml). After drying at 55°C under vacuum, (S)-Pregabalin was obtained as white crystals in a 90% yield.

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2017019791&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCT+Biblio

/////////////// (S)-pregabalin, WO 2017019791