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In a press release the EDQM has announced that the new monograph draft on Water for Injection (169) had been adopted. Read on to learn more about the production of WFI with membrane systems.

http://www.gmp-compliance.org/enews_05274_EDQM-adopts-revised-monograph-for-WFI-allowing-non-destillation-techniques_15254,15160,15090,15267,Z-PEM_n.html

In a press release, the European Pharmacopeia Commission has announced that the revised monograph on Water for Injection (WFI) had been adopted.

According to the revised monograph, it will be allowed in Europe in future to produce WFI with a purification method equivalent to distillation like e.g. reverse osmosis coupled with appropriate techniques. Moreover, the EDQM declares that a notice to the respective supervisory authorities will be required when a “non-distillation” technology is used for the production of WFI. Besides, the EDQM points out that it is not only a matter of equivalence of a specification but rather the robustness of the purification of WFI. Therefore, Annex 1, which is currently under revision, will also include requirements with…

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QP Education and Qualification – What is needed?

April 1, 2016 10:22 am / Leave a comment

DRUG REGULATORY AFFAIRS INTERNATIONAL

We are frequently asked about the educational requirements in order to become a Qualified Person in Europe. Comprehensive educational modules are offered, especially in the UK. These training courses contain different topics like pharmaceutical law, Microbiology, Quality Management etc and require the trainee to take part in multiple courses over an extended period. But is this needed to become a QP in Europe?

Read more about QP education and qualification.

see…………http://www.gmp-compliance.org/enews_05211_QP-Education-and-Qualification—What-is-needed_15432,15354,15367,S-QSB_n.html

The answer comes in two parts.

First: If you are located in the UK then those…

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IACS -9571

March 30, 2016 11:16 am / Leave a comment

IACS-9571

TRIM24/BRPF1 bromodomain inhibitor

IACS-9571; IACS 9571; IACS9571.

Molecular Formula:	C₃₂H₄₂N₄O₈S
Molecular Weight:	642.76288 g/mol

N-[6-[3-[4-(dimethylamino)butoxy]-5-propoxyphenoxy]-1,3-dimethyl-2-oxobenzimidazol-5-yl]-3,4-dimethoxybenzenesulfonamide

BOARD OF REGENTS, UNIVERSITY OF TEXAS SYSTEM

IACS-9571 is a potent and selective inhibitor TRIM24 and BRPF1. The bromodomain containing proteins TRIM24 (Tripartite motif containing protein 24) and BRPF1 (bromodomain and PHD finger containing protein 1) are involved in the epigenetic regulation of gene expression and have been implicated in human cancer. Overexpression of TRIM24 correlates with poor patient prognosis and BRPF1 is a scaffolding protein required for the assembly of histone acetyltransferase complexes, where the gene of MOZ (monocytic leukemia zinc finger protein) was first identified as a recurrent fusion partner in leukemia patients (8p11 chromosomal rearrangements). IACS-9571 has low nanomolar affinities for TRIM24 and BRPF1 (ITC Kd = 31 nM and 14 nM, respectively). With its excellent cellular potency (EC50 = 50 nM) and favorable pharmacokinetic properties (F = 29%), IACS-9571 is a high-quality chemical probe for the evaluation of TRIM24 and/or BRPF1 bromodomain function in vitro and in vivo. (J Med Chem. 2015 Jun 10. [Epub ahead of print] )

PAPER

http://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.5b00405

Structure-Guided Design of IACS-9571, a Selective High-Affinity Dual TRIM24-BRPF1 Bromodomain Inhibitor

^†Institute for Applied Cancer Science, and ^‡Core for Biomolecular Structure and Function, The University of Texas MD Anderson Cancer Center, 1881 East Road, Unit 1956, Houston, Texas 77054, United States

^§ Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center,

1515 Holcombe Boulevard

, Houston, Texas 77030, United States

J. Med. Chem., 2016, 59 (4), pp 1440–1454

DOI: 10.1021/acs.jmedchem.5b00405

Publication Date (Web): June 10, 2015

*E-mail: wpalmer@mdanderson.org. Telephone: (001) 713-745-3022. Fax: (001) 713-745-8865.

The bromodomain containing proteins TRIM24 (tripartite motif containing protein 24) and BRPF1 (bromodomain and PHD finger containing protein 1) are involved in the epigenetic regulation of gene expression and have been implicated in human cancer. Overexpression of TRIM24 correlates with poor patient prognosis, and BRPF1 is a scaffolding protein required for the assembly of histone acetyltransferase complexes, where the gene of MOZ (monocytic leukemia zinc finger protein) was first identified as a recurrent fusion partner in leukemia patients (8p11 chromosomal rearrangements). Here, we present the structure guided development of a series of N,N-dimethylbenzimidazolone bromodomain inhibitors through the iterative use of X-ray cocrystal structures. A unique binding mode enabled the design of a potent and selective inhibitor 8i (IACS-9571) with low nanomolar affinities for TRIM24 and BRPF1 (ITC K_d = 31 nM and ITC K_d = 14 nM, respectively). With its excellent cellular potency (EC₅₀ = 50 nM) and favorable pharmacokinetic properties (F = 29%), 8i is a high-quality chemical probe for the evaluation of TRIM24 and/or BRPF1 bromodomain function in vitro and in vivo.

TFA salt of 8i (106 mg, 57%) as a white solid. 1H NMR (600 MHz, DMSO-d6) δ 9.46 (s, 1H), 9.30 (br-s, 1H), 7.19 (m, 2H), 7.07 (s, 1H), 6.90 (d, J = 9.0 Hz, 1H), 6.75 (s, 1H), 6.13 (t, J = 2.2 Hz, 1H), 5.71 (t, J = 2.0 Hz, 1H), 5.67 (t, J = 2.0 Hz, 1H), 3.84 (t, J = 5.9 Hz, 2H), 3.77 (m, 5H), 3.62 (s, 3H), 3.29 (s, 3H), 3.20 (s, 3H), 3.12–3.05 (m, 2H), 2.78 (d, J = 4.7 Hz, 6H), 1.77–1.63 (m, 6H), 0.95 (t, J = 7.3 Hz, 3H). 13C NMR (600 MHz, DMSO-d6) δ 160.3, 160.0, 159.3, 154.1, 152.0, 148.4, 143.9, 131.8, 128.2, 126.0, 121.9, 120.5, 110.4, 109.4, 106.4, 100.6, 95.9, 95.8, 95.2, 68.9, 66.7, 56.3, 55.6, 55.4, 42.1, 27.1, 27.0, 25.6, 21.9, 20.7, 10.4. MS (ESI) m/z 644 [M + H]+.

NMR

IACS -9571

STR2

N-(6-(3-(4-(dimethylamino)butoxy)-5- propoxyphenoxy)-l,3-dimethyl-2-oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-3,4- dimethoxybenzenesulfonamide 2,2,2-trifluoroacetate

CLICK ON IMAGE

ABSTRACT

251st ACS National Meeting & Exposition

13–17 March 2016

San Diego, United States

MEDI 5

Discovery and development of a potent dual TRIM24/BRPF1 bromodomain inhibitor, IACS -9571, using structure- based drug design Wylie S. Palmer 1 , wpalmer@mdanderson.org, Guillaume Poncet -Montagne 1 , Gang Liu 1 , Alessia Petrocchi 1 , N aphtali Reyna 1 , Govindan Subramanian 1 , Jay Theroff 1 , Maria Kost -Alimova 1 , Jennifer Bardenhagen 1 , Elisabetta Leo 1 , Hannah Sheppard 1 , Trang Tieu 1 , Shi Xi 1 , Yanai Zhan 1 , Shuping Zhao 1 , Michelle Barton 2 , Giulio Draetta 1 , Carlo Toniatti 1 , Philip Jones 1 , Mary Ge ck Do 1 , Jannik Andersen 1 . (1) Institute for Applied Cancer Science, The University of Texas, MD Anderson Cancer Center, Houston, Texas, United States (2) Department of Epigenetics and Molecular Carcinogenesis, The University of Texas, MD Anderson Cancer Center, Houston, Texas, United States

Bromodomains are an important class of chromatin remodeling proteins that recognize acetylated lysine residues on histone tails. As epigenetic targets they regulate gene transcription and offer a new way to treat diseas es, particularly in inflammation and oncology. The bromodomain and extra- terminal (BET) family has emerged as an important and druggable example of this class of proteins with the successful entry of small- molecule inhibitors into the clinic. Other families of bromodomains are only starting to be explored, such as the Tripartite Motif -containing 24 protein (TRIM24) and bromodomain- PHD finger protein 1 (BRPF1). Both proteins contain a dual PHD -bromo motif which have a role in recognizing specific histone mar ks. TRIM24 recognizes the dual histone marks of unmodified H3K4 and acetylated- H3K23 within the same histone tail. TRIM24 is a potent co- activator of ER -alpha and overexpression of TRIM24 has been linked to poor survival rates in breast cancer patients.

This presentation will describe the structure guided development of a series of N,N- dimethyl -benzimidazolones through the iterative use of X -ray cocrystal structures. A unique binding mode enabled the design of a potent and selective inhibitor (IACS -9571) with low nanomolar affinities for TRIM24 and BRPF1 (ITC Kd = 31 nM and ITC Kd = 14 nM, respectively). With its excellent cellular potency (EC 50 = 50 nM) and favorable pharmacokinetic properties, IACS -9571 is a high- quality chemical probe for the evaluation of TRIM24 and/or BRPF1 bromodomain function in vitro and in vivo

PATENT

WO-2016033416-A1

Synthesis of Intermediates:

N-(6-bromo-l ,3-dimethyl-2-oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-2,2,2- trifluoroacetamide (Intermediate 1):

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Step 1 : 5-nitro-lH-benzo[d]imidazol-2(3H)-one:

To a 0 °C solution of 4-nitrobenzene- 1 ,2-diamine (44 g, 285 mmol) in 80 mL of DMF was added l, l’-carbonyldiimidazole (70 g, 428 mmol). The reaction mixture was stirred at RT for 4 h, then water (250 mL) was added. The resulting suspension was filtered, and the collected solids were washed with water (200 mL) and dried to give 5-nitro-lH- benzo[d]imidazol-2(3H)-one as a yellow solid (45 g, 88%). MS (ES+) C7H5N3O3 requires: 179, found: 180 [M+H]⁺.

Step 2: l,3-dimethyl-5-nitro-lH-benzo[d]imidazol-2(3H)-one:

To a solution of 5-nitro-lH-benzo[d]imidazol-2(3H)-one (55 g, 309 mmol) in 150 mL of DMF was added K2CO3 (85 g, 618 mmol), the reaction mixture was cooled to 0 °C, then iodomethane (109 g, 772 mmol) was slowly added. The reaction mixture was stirred at RT overnight, then water was added to the reaction mixture. The resulting suspension was filtered and the collected solids were washed with water (200 mL) and dried to give 1,3- dimethyl-5-nitro-lH-benzo[d]imidazol-2(3H)-one as a yellow solid (55 g, 86%). MS (ES+) C9H9N3O3 requires: 207, found: 208 [M+H] ⁺.

Step 3: 5-amino-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one:

To a solution of l,3-dimethyl-5-nitro-lH-benzo[d]imidazol-2(3H)-one (50 g, 240 mmol) in 200 mL of EtOAc under an inert atmosphere was added 10% palladium on activated carbon (5 g, 24 mmol). The reaction mixture was then charged with hydrogen and stirred at RT under an ¾ atmosphere overnight. The reaction mixture was filtered through a pad of celite then concentrated to give 5-amino-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)- one as a yellow solid (32 g, 68%). MS (ES+) C9H11N3O requires: 177, found: 178 [M+H]⁺.

Step 4: 5-amino-6-bromo-l ,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one:

To a 0 °C solution of 5-amino-l ,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one (4 g, 22.6 mmol) in 25 mL of CHCI3 and 25 mL of AcOH was slowly added drop wise bromine (3.5 g, 22.6mmol). The mixture was stirred at RT for 30 min, then concentrated and purified by silica gel chromatography (1 : 1 EtOAc/ hexanes) to afford 5-amino-6-bromo-l ,3-dimethyl- lH-benzo[d]imidazol-2(3H)-one as a yellow solid (3.2 g, 69%). MS (ES+) C₉HioBrN₃0 requires: 256, found: 257 [M+H]⁺.

Step 5: N-(6-bromo-l ,3-dimethyl-2-oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-2,2,2- trifluoroacetamide:

To a 0 °C solution of 5-amino-6-bromo-l ,3-dimethyl-lH-benzo[d]imidazol- 2(3H)-one (1.50 g, 5.9 mmol) in DCM (45 ml) was added DMAP (72 mg, 0.59 mmol), triethylamine (1.63 ml, 11.7 mmol) and trifluoroacetic anhydride (0.91 ml, 6.4 mmol). The reaction mixture was stirred for 2 h and warmed to RT. The reaction mixture was then quenched with water and the organic phase was washed with brine, dried over sodium sulfate, filtered and concentrated to give N-(6-bromo-l,3-dimethyl-2-oxo-2,3-dihydro-lH- benzo[d]imidazol-5-yl)-2,2,2-trifluoroacetamide (Intermediate 1) as a yellow solid (2.20 g, 100%). MS (ES+) CiiH₉BrF₃N302 requires: 352, found 353 [M+H]⁺.

5-amino-6-(3-hydroxyphenoxy)-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one (Intermediate 2, Route A):

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To a mixture of 5-amino-6-(3-(benzyloxy)phenoxy)-l,3-dimethyl-lH- benzo[d]imidazol-2(3H)-one (400 mg, 1.07 mmol) in DCM (20 mL) at -78 °C was added tribromoborane (5.3 mL, 5.3 mmol). The mixture was warmed up to room temperature gradually, then quenched by methanol dropwise, concentrated, and purified by column chromatography (20-100% EtOAc/hexanes and then 0-40% methanol/EtOAc) to give 5- amino-6-(3-hydroxyphenoxy)-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one as a solid (240 mg, 79%). MS (ES+) C15H15N3O3 requires: 285, found: 286 [M+H]⁺.

5-amino-6-(3-hydroxyphenoxy)-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one (Intermediate 2, Route B):

Step 2

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Step 1: 3-[(ieri-butyldimethylsilyl)oxy]phenol:

A mixture of lH-imidazole (2.25 g, 33.1 mmol), ieri-butylchlorodimethylsilane (3.83 g, 25.4 mmol) and resorcinol (5.6 g, 51 mmol) in THF (30 ml) was stirred at 80 °C for 5 h. The resulting suspension of the cooled reaction mixture was filtered and the collected filtrate was concentrated and purified by silica-gel chromatography (20:80 to 0:100, EtOAc/hexanes) to give 3-((ieri-butyldimethylsilyl)oxy)phenol (2.78 g, 49%). MS (ES+) C12H20O2S1 requires: 224, found 225 [M+H]⁺.

Step 2: 5-amino-6-(3-((ier^butyldimethylsilyl)oxy)phenoxy)-l ,3-dimethyl-lH- benzo[d]imidazol-2(3H)-one:

A mixture of 3-((ieri-butyldimethylsilyl)oxy)phenol (1.39 g, 6.20 mmol), quinolin-8-ol (79 mg, 0.55 mmol), copper(I) chloride (20 mg, 0.21 mmol), potassium phosphate (526 mg, 2.48 mmol) and 5-amino-6-bromo-l ,3-dimethyl-lH-benzo[d]imidazol- 2(3H)-one (529 mg, 2.07 mmol) in diglyme (20 ml) in a 100 mL round-bottom flask was degassed under a nitrogen atmosphere and heated to 120 °C for 24 h. To the cooled reaction mixture was added silica gel, stirred for 2 min, then the mixture was filtered through a pad of silica gel. The collected filtrate was concentrated and purified by column chromatography (20:80 to 0: 100, EtOAc/hexanesthen 0: 100 to 40:60, MeOH/EtOAc) to give 5-amino-6-(3- ((ieri-butyldimethylsilyl)oxy)phenoxy)-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one (521 mg, 63%). MS (ES+) C21H29N3O3S1 requires: 399, found 400 [M+H]⁺.

Step 3: 5-amino-6-(3-hydroxyphenoxy)-l,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one:

To a 0 °C solution of 5-amino-6-(3-((ieri-butyldimethylsilyl)oxy)phenoxy)-l,3- dimethyl-lH-benzo[d]imidazol-2(3H)-one (623 mg, 1.56 mmol) in THF was added a solution of ieira-butylammonium fluoride (0.90 mL, 3.1 mmol) in THF, the reaction mixture was allowed to warm up to RT and then stirred for 1-2 h. The reaction mixture was quenched with 1 M hydrogen chloride (0.10 mL, 3.1 mmol) and then partitioned between EtOAc and water. The seperated organic layer was washed with water twice, then concentrated and purified by column chromatography (20-80% EtOAc/hexanes and 0-40% MeOH/DCM) to give 5-amino-6-(3-hydroxyphenoxy)-l ,3-dimethyl-lH-benzo[d]imidazol-2(3H)-one (120 mg, 27%) as a solid. MS (ES+) C15H15N3O3 requires: 285, found 286 [M+H]⁺.

EXAMPLE 10: N-(6-(3-(4-(dimethylamino)butoxy)-5-propoxyphenoxy)-l,3-dimethyl-2- oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-3,4-dimethoxybenzenesulfonamide 2,2,2-

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To a solution of N-(6-(3-(4-aminobutoxy)-5-propoxyphenoxy)-l ,3-dimethyl-2- oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-3,4-dimethoxybenzenesulfonamide 2,2,2- trifluoroacetate (180 mg, 0.247 mmol) in methanol (3.0 ml) was added triethylamine (0.034 ml, 0.25 mmol), acetic acid (0.028 ml, 0.49 mmol), formaldehyde (0.054 ml, 2.0 mmol), and sodium triacetoxyborohydride (131 mg, 0.618 mmol). The reaction mixture was stirred at room temperature and checked by LCMS every 30 minutes. After 3 h the reaction was complete by LCMS. The reaction was quenched with a few drops of TFA and concentrated under reduced pressure. The residue was purified by prep-HPLC using a gradient of 20-60% ACN/water containing 0.1% TFA to afford N-(6-(3-(4-(dimethylamino)butoxy)-5- propoxyphenoxy)-l,3-dimethyl-2-oxo-2,3-dihydro-lH-benzo[d]imidazol-5-yl)-3,4- dimethoxybenzenesulfonamide 2,2,2-trifluoroacetate (106 mg, 57%) as a white solid. MS (ES+) C32H42N4O8S requires: 642, found 643 [M+H]⁺. ¾ NMR (600 MHz, DMSO-ifc) δ 9.46 (s, 1H), 9.30 (br-s, 1H), 7.19 (m, 2H), 7.07 (s, 1H), 6.90 (d, 7 = 9.0 Hz, 1H), 6.75 (s, 1H), 6.13 (t, 7 = 2.2 Hz, 1H), 5.71 (t, J = 2.0 Hz, 1H), 5.67 (t, J = 2.0 Hz, 1H), 3.84 (t, 7 = 5.9 Hz, 2H), 3.77 (m, 5H), 3.62 (s, 3H), 3.29 (s, 3H), 3.20 (s, 3H), 3.12-3.05 (m, 2H), 2.78 (d, 7 = 4.7 Hz, 6H), 1.77-1.63 (m, 6H), 0.95 (t, 7 = 7.3 Hz, 3H)

References

1: Palmer WS, Poncet-Montange G, Liu G, Petrocchi A, Reyna N, Subramanian G, Theroff J, Yau A, Kost-Alimova M, Bardenhagen JP, Leo E, Shepard HE, Tieu TN, Shi X, Zhan Y, Zhao S, Draetta G, Toniatti C, Jones P, Geck Do M, Andersen JN. Structure-Guided Design of IACS-9571, a Selective High-Affinity Dual TRIM24-BRPF1 Bromodomain Inhibitor. J Med Chem. 2015 Jun 10. [Epub ahead of print] PubMed PMID: 26061247.

US-20160060260-A1

Institute for Applied Cancer Science, The University of Texas, MD Anderson Cancer Center, Houston, Texas, United States

The University of Texas MD Anderson Cancer Center | University of Texas System

The new Institute for Applied Cancer Science will be located at the south campus of M.D.

Draetta arrived at MD Anderson in 2011 to direct the Institute for Applied Cancer Science. He oversees the moon shots platforms

Department of Epigenetics and Molecular Carcinogenesis, The University of Texas, MD Anderson Cancer Center, Houston, Texas, United States

///////IACS-9571, TRIM24, BRPF1 bromodomain inhibitor, IACS-9571, IACS 9571, IACS9571, BOARD OF REGENTS, UNIVERSITY OF TEXAS SYSTEM
CAS BASE 1800477-30-8
CAS OF 1:1 TRIFLUOROACETATE 1883598-69-3

c1(cc(cc(c1)OCCC)Oc3cc2N(C(N(c2cc3NS(=O)(=O)c4cc(c(cc4)OC)OC)C)=O)C)OCCCCN(C)C

CCCOC1=CC(=CC(=C1)OC2=C(C=C3C(=C2)N(C(=O)N3C)C)NS(=O)(=O)C4=CC(=C(C=C4)OC)OC)OCCCCN(C)C

HELP, Need one time help to pay 10 year concessional subscription to this, your favorite blog to WordPress

March 30, 2016 3:23 am / Leave a comment

New Drug Approvals

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Tianagliflozin IND filed by Tianjin Institute of Pharmaceutical research

March 30, 2016 3:20 am / Leave a comment

Tianagliflozin,

taigeliejing, 6-deoxydapagliflozin

Molecular Formula:	C₂₁H₂₅ClO₅
Molecular Weight:	392.8732 g/mol

Tianjin Institute Of Pharmaceutical Research,

(3R,4S,5S,6R)-2-[4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl]-6-methyloxane-3,4,5-triol

1-[4-Chloro-3-(4-ethoxybenzyl)phenyl]-1,6-dideoxy-b-D-glucopyranose

D-Glucitol, 1,5-anhydro-1-C-[4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl]-6-deoxy-, (1S)-

1–[4–Chloro–3–(4–ethoxybenzyl)phenyl]–1,6–dideoxy–β–d–glucopyranose

6-deoxydapagliflozin

https://pubchem.ncbi.nlm.nih.gov/compound/67891767#section=Top

A SGLT-2 inhibitor potentially for the treatment of type 2 diabetes.

CAS N. 1461750-27-5

The structures of dapagliflozin and 6-deoxydapagliflozin (1)

,deletion of the 6-OH in the sugar moiety of dapagliflozin led to the discovery of a more potent SGLT2 inhibitor, 6-deoxydapagliflozin (1, ). In an in vitro assay, 1 was a more active SGLT2 inhibitor, with IC ₅₀ = 0.67 nM against human SGLT2 (hSGLT2), as compared with 1.1 nM for dapagliflozin, leading to the identification of 1 as the most active SGLT2 inhibitor discovered so far in this field. Also in an in vivo assay, 1 also introduced more urinary glucose in a rat urinary glucose excretion test (UGE) and exhibited more potent blood glucose inhibitory activity in a rat oral glucose tolerance test (OGTT) than dapagliflozin.

Given the fact that 6-dexoydapagliflozin (1) is a very promising SGLT2 inhibitor that could be used to treat type 2 diabetes, led to preclinical trials

 Tianjin Institute Of Pharmaceutical Research,天津药物研究院

SPECTRAL DATA of Tianagliflozin

1 as a white solid (3.65 g, 93 %). R _f = 0.35 (EtOAc);

m.p.: 148–149 °C;

¹H NMR (400 MHz, DMSO-d ₆): δ = 7.35 (d, 1H, J = 8.4 Hz), 7.25 (s, 1H), 7.18 (d, 1H, J = 8.0 Hz), 7.08 (d, 2H, J = 8.4 Hz), 6.81 (d, 2H, J = 8.4 Hz), 4.95 (d, 1H, J = 5.2 Hz, OH), 4.90 (d, 1H, J = 4.4 Hz, OH), 4.79 (d, 1H, J = 5.6 Hz, OH), 3.92–4.01 (m, 5H), 3.24–3.29 (m, 1H), 3.18–3.22 (m, 1H), 3.09–3.15 (m, 1H), 2.89–2.95 (m, 1H), 1.29 (t, 3H, J = 7.0 Hz, CH₂ CH ₃), 1.15 (d, 3H, J = 6.0 Hz, CHCH ₃) ppm;

¹³C NMR (100 MHz, DMSO-d ₆): δ = 156.85, 139.65, 137.82, 131.83, 131.16, 130.58, 129.52, 128.65, 127.14, 114.26, 80.71, 77.98, 75.77, 75.51, 74.81, 62.84, 37.55, 18.19, 14.62 ppm;

IR (KBr): v¯¯¯ = 3,564 (w), 3,385 (s), 2,981 (s), 2,899 (s), 2,861 (s), 1,613 (m), 1,512 (s), 1,477 (m), 1,247 (s), 1,102 (s), 1,045 (s), 1,012 (s) cm⁻¹;

HR–MS: calcd for C₂₁H₂₉ClNO₅ ([M + NH₄]⁺) 410.1729, found 410.1724.

PATENT

CN 103864737

http://www.google.com/patents/CN103864737A?cl=en

PATENT

WO 2014094544

http://www.google.com/patents/WO2014094544A1?cl=en

Figure imgf000032_0001

-27-

1 D1 -6 Optionally, the step (7 ‘) is the step (7’) in place:

LS l- [4 – D (I- Dl- 6)

(DMSO-d _6, 400 MHz), δ 7.35 (d, 1H, J = 8.0 Hz), 7.28 (d, 1H, J ‘. 2.0 Hz), 7.17 (dd, IH, / = 2.0 Hz and 8.4 Hz), 7.05 (d, 2H, _J: 8.8 Hz), 6.79 (d, 2H, 8.8 Hz): 4.924,95 (m, 2H), 4,81 (d, IH, 6,0 Hz), 3.93- 3.99 (m, 5H), 3,85 (d, 1H, J = 10,4 Hz), 3,66 (dd, IH, 5,2 Hz and 11,6 Hz), 3.17-3,28 (m, 3H), 3.02-3.08 _(m: IH), 1.28 (t, 3H, J = 7,0 Hz), 0,80 (s, 9H), -0.05 (s, 3H), -0.09 (s, 3H) .

PATENT

CN 104045614

[0066] The added 100mL dried over anhydrous methanol 0. 5g of sodium metal, nitrogen at room temperature with stirring, until the sodium metal disappeared. Followed by addition of 5. 2g (10mmol) of compound 6, stirring was continued at room temperature for 3 hours. To the reaction system was added 5g strong acid cation exchange resin, stirred at room temperature overnight, the reaction mixture until pH = 7. The resin was removed by suction, and the filtrate evaporated to dryness on a rotary evaporator, the residue was further dried on a vacuum pump to give the product I-D1-6, as a white foamy solid.

PATENT

WO 2014139447

http://link.springer.com/article/10.1007%2Fs40242-014-4043-9#/page-1

Med Chem. 2015;11(4):317-28.

Design of SGLT2 Inhibitors for the Treatment of Type 2 Diabetes: A History Driven by Biology to Chemistry.

Cai W, Jiang L, Xie Y, Liu Y, Liu W, Zhao G¹.

Abstract

A brief history of the design of sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors is reviewed. The design of O-glucoside SGLT2 inhibitors by structural modification of phlorizin, a naturally occurring O-glucoside, in the early stage was a process mainly driven by biology with anticipation of improving SGLT2/SGLT1 selectivity and increasing metabolic stability. Discovery of dapagliflozin, a pioneering C-glucoside SGLT2 inhibitor developed by Bristol-Myers Squibb, represents an important milestone in this history. In the second stage, the design of C-glycoside SGLT2 inhibitors by modifications of the aglycone and glucose moiety of dapagliflozin, an original structural template for almost all C-glycoside SGLT2 inhibitors, was mainly driven by synthetic organic chemistry due to the challenge of designing dapagliflozin derivatives that are patentable, biologically active and synthetically accessible. Structure-activity relationships (SAR) of the SGLT2 inhibitors are also discussed.

http://www.ncbi.nlm.nih.gov/pubmed/25557661

Paper

Discovery of 6-Deoxydapagliflozin as a Highly Potent Sodium-dependent Glucose Cotransporter 2 (SGLT2) Inhibitor for the Treatment of Type 2 Diabetes

Authors: Zhang, Lingyu; Wang, Yuli; Xu, Huaqiang; Shi, Yongheng; Liu, Bingni; Wei, Qunchao; Xu, Weiren; Tang, Lida; Wang, Jianwu; Zhao, Guilong

Source: Medicinal Chemistry, Volume 10, Number 3, May 2014, pp. 304-317(14)

http://www.ingentaconnect.com/content/ben/mc/2014/00000010/00000003/art00009?crawler=true

CLIP

A facile synthesis of 6-deoxydapagliflozin

Keywords. Carbohydrates Drug research Hydrogenolysis Dapagliflozin SGLT2 inhibitor

http://link.springer.com/article/10.1007/s00706-013-1053-0/fulltext.html

The synthetic route to the target compound 1 is shown in Scheme 3. The starting material methyl 2,3,4-tri-O-benzyl-6-deoxy-6-iodo-α–d-glucopyranoside (3) was prepared from commercially available methyl α–d-glucopyranoside (2) according to a known method [5, 6].

Iodide 3 was reductively deiodinated to give 4 in 91 % yield under hydrogenolytic conditions using 10 % Pd/C as catalyst in the presence of Et₃N as base in THF/MeOH at room temperature.

when the iodide 3 was treated with Barton–McCombie reagent (n-Bu₃SnH/AIBN) [7] in toluene at room temperature no reaction occurred; however, when the reaction was carried out at elevated temperatures, such as reflux, a complex mixture formed with only a trace amount (3 %, entry 1) of the desired product 4.

When the iodide 3 was treated with LiAlH₄ in THF at 0 °C to room temperature, another complex mixture was produced with only a trace amount (2 %, entry 2) of 4.

When Pd(OH)₂ was used as the hydrogenolysis catalyst instead of 10 % Pd/C, the desired 4 was indeed formed (14 %, entry 4), but most of the starting material was converted to a few more polar byproducts, which were believed to result from the cleavage of at least one of the benzyl groups.

pdf available

Monatshefte für Chemie – Chemical Monthly

December 2013, Volume 144, Issue 12, pp 1903-1910

http://download.springer.com/static/pdf/721/art%253A10.1007%252Fs00706-013-1053-0.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs00706-013-1053-0&token2=exp=1458808857~acl=%2Fstatic%2Fpdf%2F721%2Fart%25253A10.1007%25252Fs00706-013-1053-0.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs00706-013-1053-0*~hmac=bd1c3c2bdc3712f5540267c99f732b2f7588020a868aa23021792a2a2a58d65e

References

1.Washburn WN (2009) J Med Chem 52:1785
2.Hardman TC, Dubrey SW (2011) Diabetes Ther 2:133
3.Meng M, Ellsworth BA, Nirschl AA, McCann PJ, Patel M, Girotra RN, Wu G, Sher PM, Morrison EP, Biller SA, Zahler R, Deshpande PP, Pullockaran A, Hagan DL, Morgan N, Taylor JR, Obermeier MT, Humphreys WG, Khanna A, Discenza L, Robertson JM, Wang A, Han S, Wetterau JR, Janovitz EB, Flint OP, Whaley JM, Washburn WN (2008) J Med Chem 51:1145
4.Nomura S, Sakamaki S, Hongu M, Kawanishi E, Koga Y, Sakamoto T, Yamamoto Y, Ueta K, Kimata H, Nakayama K, Tsuda-Tsukimoto M (2010) J Med Chem 53:6355
5.Lee JC, Francis S, Georg GI, Dutta D, Gupta V, Tash JS, Yang Y, Zhu J-Y, Schoenbrunn E (2012) J Org Chem 77:3082
6.Bartoszewicz A, Kalek M, Stawinski J (2008) Tetrahedron 64:8843
7.Zhao GL, Lou YY, Zhang LS, Shao H, Xu WR, Tang LD, Zou MX (2012) Synth Commun 42:2885
8.Koto S, Morishima N, Miyata Y, Zen S (1976) Bull Chem Soc Jpn 49:2639
9.Kakinuma H, Oi T, Hashimoto-Tsuchiya Y, Arai M, Kawakita Y, Fukasawa Y, Iida I, Hagima N, Takeuchi H, Chino Y, Asami J, Okumura-Kitajima L, Io F, Yamamoto D, Miyata N, Takahashi T, Uchida S, Yamamoto K (2010) J Med Chem 53:3247
10.Xu J, Egger A, Bernet B, Vasella A (1996) Helv Chim Acta 79:2004
11.Lee SH, Song K-S, Kim JY, Kang M, Lee JS, Cho S-H, Park H-J, Kim J, Lee J (2011) Bioorg Med Chem 19:5813
12.Song K-S, Lee SH, Kim MJ, Seo HJ, Lee J, Lee S-H, Jung ME, Son E-J, Lee MW, Kim J, Lee J (2011) ACS Med Chem Lett 2:182
13.Lee J, Lee S-H, Seo HJ, Son E-J, Lee SH, Jung ME, Lee MW, Han HK, Kim J, Kang J, Lee J (2010) Bioorg Med Chem 18:2178
14.Kim MJ, Lee SH, Park SO, Kang H, Lee JS, Lee KN, Jung ME, Kim J, Lee J (2011) Bioorg Med Chem 19:5468
15.Skaanderup PR, Poulsen CS, Hyldtoft L, Jørgensen MR, Madsen R (2002) Synthesis 1721
Monatshefte fuer Chemie (2013), 144(12), 1903-1910
Medicinal Chemistry (Sharjah, United Arab Emirates) (2014), 10(3), 304-317
Chinese Journal of Structural Chemistry (2014), 33(1), 85-89
Xiandai Yaowu Yu Linchuang (2013), 28(6), 838-841
Chemical Research in Chinese Universities (2014), 30(5), 785-793

////////, SGLT-2 inhibitor, type 2 diabetes, Tianagliflozin, taigeliejing, 6-deoxydapagliflozin, 1461750-27-5

Clc1c(cc(cc1)C2[C@@H]([C@H]([C@@H]([C@H](O2)C)O)O)O)Cc3ccc(cc3)OCC

CCOC1=CC=C(C=C1)CC2=C(C=CC(=C2)C3C(C(C(C(O3)C)O)O)O)Cl

c1(c(cc(cc1)C2OC(C(C(C2O)O)O)C)Cc3ccc(cc3)OCC)Cl

BRIVARACETAM

March 23, 2016 11:48 am / Leave a comment

BRIVARACETAM, UCB-34714

(2S)-2-[(4R)-2-oxo-4-propylpyrrolidin-1-yl]butanamide

(2S)-2-[(4R)-2-Oxo-4-propyl-1-pyrrolidinyl]butanamide

1-Pyrrolidineacetamide, α-ethyl-2-oxo-4-propyl-, (αS,4R)-

CAS 357336-20-0

Molecular Formula:	C₁₁H₂₀N₂O₂
Molecular Weight:	212.2887 g/mol

UNII-U863JGG2IA

UCB; For the treatment of partial onset seizures related to epilepsy, Approved February 2016

Brivaracetam, the 4-n-propyl analog of levetiracetam, is a racetam derivative with anticonvulsant properties.^[1]^[2] Brivaracetam is believed to act by binding to the ubiquitous synaptic vesicle glycoprotein 2A (SV2A).^[3] Phase II clinical trials in adult patients with refractory partial seizures were promising. Positive preliminary results from stage III trials have been recorded,^[4]^[5] along with evidence that it is around 10 times more potent^[6] for the prevention of certain types of seizure in mouse models than levetiracetam, of which it is an analogue.

On 14 January 2016, the European Commission,^[7] and on 18 February 2016, the USFDA^[8] approved brivaracetam under the trade name Briviact (by UCB). The launch of this anti-epileptic is scheduled for the first quarter of that year. Currently, brivaracetam is still not approved in other countries like Australia, Canada and Switzerland.

Brivaracetam was approved by European Medicine Agency (EMA) on Jan 14, 2016 and approved by the U.S. Food and Drug Administration (FDA) on Feb 18, 2016. It was developed and marketed as Briviact^® by UCB in EU/US.

Brivaracetam is a selective high-affinity synaptic vesicle protein 2A ligand, as an adjunctive therapy in the treatment of partial-onset seizures with or without secondary generalization in adult and adolescent patients from 16 years of age with epilepsy.

Briviact^® is available in three formulations, including film-coated tablets, oral solution and solution for injection/infusion. And it will be available as 10 mg, 25 mg, 50 mg, 75 mg and 100 mg film-coated tablets, a 10 mg/ml oral solution, and a 10 mg/ml solution for injection/infusion. The recommended starting dose is either 25 mg twice a day or 50 mg twice a day, depending on the patient’s condition. The dose can then be adjusted according to the patient’s needs up to a maximum of 100 mg twice a day. Briviact can be given by injection or by infusion (drip) into a vein if it cannot be given by mouth.

European Patent No. 0 162 036 Bl discloses compound (S)-α-ethyl-2-oxo-l- pyrrolidine acetamide, which is known under the International Non-proprietary Name of Levetiracetam.

Levetiracetam

Levetiracetam is disclosed as a protective agent for the treatment and prevention of hypoxic and ischemic type aggressions of the central nervous system in European patent EP 0 162 036 Bl. This compound is also effective in the treatment of epilepsy.

The preparation of Levetiracetam has been disclosed in European Patent No. 0 162 036 and in British Patent No. 2 225 322.

International patent application having publication number WO 01/62726 discloses 2-oxo-l -pyrrolidine derivatives and methods for their preparation. It particularly discloses compound (2S)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-l-yl] butanamide known under the international non propriety name of brivaracetam.

Brivaracetam

International patent application having publication number WO 2005/121082 describes a process of preparation of 2-oxo-l -pyrrolidine derivatives and particularly discloses a process of preparation of (2S)-2-[(4S)-4-(2,2-difluorovinyl)-2-oxo-pyrrolidin-l- yl]butanamide known under the international non propriety name of seletracetam.

Seletracetam

Kenda et al., in J. Med. Chem. 2004, 47, 530-549, describe processes of preparation of 2-oxo-l -pyrrolidine derivatives and particularly discloses compound 1-((1S)-I- carbamoyl-propyl)-2-oxo-pyrrolidone-3-carboxylic acid as a synthetic intermediate.

WO2005028435

CLIPS

Find better ways to make old and new epilepsy drugs. J. Surtees and co-inventors disclose alternative processes for making active pharmaceutical ingredients (APIs) that are used to treat epilepsy and seizures. One compound that can be prepared by their processes is the established drug levetiracetam (1, Figure 1), marketed under the trade name Keppra. Because 1 is now off-patent, there is obvious interest in new drugs.

The inventors also claim that seletracetam (2) and brivaracetam (3) (Figure 2) can be prepared by their processes. These drugs are apparently much more active than 1.

All of the drugs are used as single isomers, so a stereoselective synthesis is desirable. The inventors describe two routes for preparing the molecules; the first, shown in Figure 1, is the synthesis of 1 by the reaction between pyrrolidone (4) and chiral bromo amide 5 in the presence of a base. GC analysis showed that the conversion is 40.3% and that the product contains 51% of the (S)-enantiomer and 49% of the (R)-isomer. No details of their separation are given, although the use of chiral HPLC is discussed.

The same reaction is used to prepare derivative 6 of 1. Compound 7 is prepared from the corresponding hydroxy ester and then condensed with 4 to give 6. Chiral HPLC showed that the product is a mixture of 89.3% (S)-enantiomer 6 and 10.7% of its (R)-isomer.

The inventors do not describe the detailed preparation of 2, but they report that acid 8 is prepared in 41% yield from pyrrolidone 9 and acid 10 in the presence of NaH (Figure 2). Ammonolysis of 8 produces 2; no reaction details are provided.

In a reaction similar to the preparation of 8, acid 11 is prepared from 10 and pyrrolidone 12. The product is isolated in 77% yield and can be converted to 3 by ammonolysis. Again, no details are provided for this reaction.

The second route for preparing the substituted pyrrolidones does not start with simple pyrrolidones and is the subject of additional claims. The route involves a cyclization reaction, shown in Figure 3. The preparation of enantiomer 13 begins with the reaction of racemic salt 14 and optically pure bromo ester 15. This step produces intermediate 16, isolated as a yellow oil. The crude material is treated with 2-hydroxypyridine (2-HP) to cyclize it to 17. This ester is hydrolyzed to give acid 18. Conversion to 13 is carried out by adding ClCO₂Et, followed by reaction with liquid NH₃ in the presence of K₂CO₃. The overall yield of 13 is 32%.

This route is also used to prepare levetiracetam (1) by treating 5 with the HCl salt of amino ester 19 to give 20, recovered as its HCl salt in 49% yield. The salt is basified with Et₃N and treated with 2-HP to cyclize it to 1, initially isolated as an oil. GC analysis showed 100% conversion, and chiral HPLC showed that the product contains 98.6% (S)-isomer and 1.4% (R)-isomer.

The inventors also prepared 1 and its (R)-enantiomer 21 by using a similar reaction scheme with alternative substrates to 5. Figure 4 outlines the route, which starts from protected hydroxy amide 22 and amino ester 23. When the reaction is carried out in the presence of Cs₂CO₃, the product is (R)-enantiomer24, which is used without purification to prepare 21 by treating it with 2-HP. Chiral HPLC showed that the product is 94% (R) and 6% (S).

When the reaction between 22 and 23 is run with K₂CO₃, the product is (S)-enantiomer 25. This is used to prepare 1, but the product contains only 79% (S)-isomer.

The inventors do not comment on the apparent stereoselectivity of the carbonate salts in the reaction of 22 with 23. This is an intriguing finding and worthy of investigation. (UCB S.A. [Brussels]. US Patent 8,338,621

SYNTHESIS

PATENT

WO2005028435

Example 1: Synthesis of (2S)-2-((4R)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide 1.1 Synthesis of (2S)-2-aminobutyramide free base

1800 ml of isopropanol are introduced in a 5L reactor. 1800 g of (2S)-2- aminobutyramide tartrate are added under stirring at room temperature. 700 ml of a 25% aqueous solution of ammonium hydroxide are slowly added while maintaining the temperature below 25°C. The mixture is stirred for an additional 3 hours and then the reaction is allowed to complete at 18°C for 1 hour. The ammonium tartrate is filtered. Yield : 86%.

1.2 Synthesis of 5-hydroxy-4-n-propyl-furan-2-one

Heptane (394 ml) and morpholine (127.5 ml) are introduced in a reactor. The mixture is cooled to 0°C and glyoxylic acid (195 g, 150 ml, 50w% in water) is added. The mixture is heated at 20°C during 1 hour, and then valeraldehyde (148.8 ml) is added . The reaction mixture is heated at 43°C during 20 hours. After cooling down to 20^CC, a 37 % aqueous solution of HCl (196.9 ml) is slowly added to the mixture, which is then stirred during 2 hours.

After removal of the heptane phase, the aqueous phase is washed three times with heptane. Diisopropyl ether is added to the aqueous phase. The organic phase is removed, and the aqueous phase further extracted with diisopropyl ether (2x). The diisopropyl ether phases are combined, washed with brine and then dried by azeotropic distillation. After filtration and evaporation of the solvent, 170g of 5- hydroxy-4-n-propyl-furan-2-one are obtained as a brown oil. Yield: 90.8 %

1.3 Synthesis of (2S)-2-((4R)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide and (2S)-2-((4S)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide

(S, R) (S, S) The (2S)-2-aιninobutyrarnide solution in isopropanol containing 250 g obtained as described here above is dried by azeotropic distillation under vacuum. To the dried (2S)-2-am obutyraιnide solution is added 5-hydroxy-4-n-propyl-furan-2-one (290 g) between 15°C and 25 °C; the mixture is heated to 30 °C and kept for at least 2 hours at that temperature. Acetic acid (1, 18 eq.), Pd/C catalyst (5 w/w%; Johnson Matthey 5% Pd on carbon – type 87L) are then added and hydrogen introduced into the system under pressure. The temperature is kept at 40 °C maximum and the H₂ pressure maintained between 0,2 bar and 0,5 bar followed by stirring for at least 20 hours following the initial reaction. The solution is then cooled to between 15 °C and 25 °C and filtered to remove the catalyst. The solution of product in isopropanol is solvent switched to a solution of product in isopropyl acetate by azeotropic distillation with isopropyl acetate. The organic solution is washed with aqueous sodium bicarbonate followed by a brine wash and then filtered. After recristallisation, 349 g of (2S)-2-((4R)-2- oxo-4-n-propyl-l-pyrrolidinyl)butanamide and (2S)-2-((4S)-2-oxo-4-n-propyl-l- pyιτolidinyl)butanamide are obtained (Yield: 82.5%).

1.4 Preparation of (2S)-2-((4R)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide The chromatographic separation of the two diastereoisomers obtained in 1.3 is performed using of (CHIRALPAK AD 20 um) chiral stationary phase and a 45/55 (volume /volume) mixture of n-heptane and ethanol as eluent at a temperature of 25 + 2°C. The crude (2S)-2-((4R)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide thus obtained is recristallised in isopropylacetate, yielding pure (2S)-2-((4R)-2-oxo-4-n-propyl-l- pyrrolidinyl)butanamide (Overall yield: 80%) .

Example 2: Synthesis of (2S)-2-((4R)-2-oxo-4-n-propyl-l-pyrrolidinyl)butanamide

Example 1 is repeated except that in step 1.1 a solution of (2S)-2- aminoburyramide.HCl in isopropanol is used (27.72 g, 1.2 equivalent), which is neutralised with a NHs/isopropanol solution (3,4-3,7 mol/L). The resulting ainmonium chloride is removed from this solution by filtration and the solution is directly used for reaction -with 5-hydroxy-4-n-propyl-furan-2-one (23.62 g, 1.0 equivalent) without intermediate drying of the (2S)-2-aminobutyramide solution. Yield after separation of the two diastereoisomers and recristallisation: approximately 84%.

Ref ROUTE1

1. WO0162726A2.

2. WO2005028435A1 / US2007100150A1.

3. J. Med. Chem. 1988, 31, 893-897.

4. J. Org. Chem. 1981, 46, 4889-4894.

PATENT

https://www.google.com/patents/WO2007031263A1?cl=en

Example 3-Synthesis of brivaracetam (I)

3.a. Synthesis of (S) and (R) 2-((R)-2-oxo-4-propyl-pyrrolidin-l-yl)-butyric acid methyl ester fVIaa^*) and (Wlab)

(VIaa) (VIab) A slurry of 60% sodium hydride suspension in mineral oil (0.94g, 23.4 mmol) in tetrahydrofuran (30 mL) is cooled at 0°C under a nitrogen atmosphere. A solution of substantially optically pure (R)-4-propyl-pyrrolidin-2-one (Ilia) (2g, 15.7 mmol) in tetrahydrofuran (2 mL) is added over a 15 minutes period. The reaction mixture is stirred 10 min at 0°C then a solution of methyl-2-bromo-butyric acid methyl ester (V) (3.69g, 20.4 mmol) in tetrahydrofuran (2mL) was added over a 20 minutes period. The reaction mixture is stirred at O⁰C until maximum conversion of starting material and the reaction mixture is then allowed to warm to room temperature and diluted with water (20 mL). Tetrahydrofuran is removed by evaporation and the residue is extracted with isopropyl acetate (20 ml + 10 mL). The combined organic layers are dried on anhydrous magnesium sulfate and evaporated to afford 3g (13.2 mmol, 86 %) of a mixture of epimers of compound (Via), as a mixture respectively of epimer (VIaa) and epimer (VIab). ¹H NMR(400 MHz, CDCI3) of the mixture of epimers (VIaa) and (VIab) : δ = 4.68

(dd, J= 10.8, J= 5.1, 2×1 H) ; 3.71 (s, 2x3H); 3.60 (t app, J= 8.2, IH); 3.42 (t app, J= 8.7, IH); 313 (dd, J= 9.2, J = 6.8, IH); 2.95 (dd, J= 9.2, J= 6.8, IH); 2.56 (dd, J= 16.6, J = 8.7, 2xlH); 2.37 (dm, 2xlH); 2.10 (m, 2xlH); 2.00 (m, 2xlH); 1.68 (m, 2xlH); 1.46 (m, 2x2H); 1.36 (m, 2x2H); 0.92 (m, 2x6H).

¹³C NMR (400 MHz, CDCl₃) of the mixture of epimers (VIaa) and (VIab) : δ =

175.9; 175.2; 171.9; 55.3; 52.4; 49.8; 49.5; 38.0; 37.8; 37.3; 36.9; 32.5; 32.2; 22.6; 22.4; 21.0; 14.4; 11.2; 11.1

HPLC (GRAD 90/10) of the mixture of epimers (VIaa) and (VIab): retention time= 9.84 minutes (100 %)

GC of the mixture of epimers (VIaa) and (VIab): retention time = 13.33 minutes (98.9 %)

MS of the mixture of epimers (VIaa) and (VIab) (ESI) : 228 MH+

3.b. Ammonolysis of compound of the mixture of (VIaa) and (VIab)

(VIaa) (VIab) (I) (VII)

A solution of (VIaa) and (VIab) obtained in previous reaction step (1.46g, 6.4 mmol) in aqueous ammonia 50 % w/w (18 mL) at 0⁰C is stirred at room temperature for 5.5hours. A white precipitate that appears during the reaction, is filtered off, is washed with water and is dried to give 0.77g (3.6 mmol, yield = 56 %) of white solid which is a mixture of brivaracetam (I) and of compound (VII) in a 1 :1 ratio.

¹H NMR of the mixture (I) and (VII) (400 MHz, CDCI3) : δ = 6.36 (s, broad, IH); 5.66 (s, broad, IH); 4.45 (m, IH); 3.53 (ddd, J= 28.8, J= 9.7, J= 8.1, IH); 3.02 (m, IH); 2.55 (m, IH); 2.35 (m, IH); 2.11 (m, IH); 1.96 (m, IH); 1.68 (m, IH); 1.38 (dm, 4H); 0.92 (m, 6H). 13c NMR of the mixture (I) and (VII) (400 MHz, CDCl₃) : δ = 176.0; 175.9; 172.8;

172.5; 56.4; 56.3; 50.0; 49.9; 38.3; 38.1; 37.3; 37.0; 32.3; 32.2; 21.4; 21.3; 21.0; 20.9; 14.4; 10.9; 10.8

HPLC (GRAD 90/10) of the mixture of (I) and (VII) retention time= 7.67 minutes (100 %)

Melting point of the mixture of (I) and (VII) = 104.9⁰C (heat from 40⁰C to 120⁰C at 10°C/min)

Compounds (I) and (VII) are separated according to conventional techniques known to the skilled person in the art. A typical preparative separation is performed on a 11.7g scale of a 1 :1 mixture of compounds (I) and (VII) : DAICEL CHIRALPAK® AD 20 μm, 100*500 mm column at 30⁰C with a 300 mL/minutes debit, 50 % EtOH – 50 % Heptane. The separation affords 5.28g (45 %) of compound (VII), retention time = 14 minutes and 5.2Og (44 %) of compounds (I), retention time = 23 minutes.

¹H NMR of compound (I) (400 MHz, CDCl₃): δ = 6.17 (s, broad, IH); 5.32 (s, broad, IH); 4.43 (dd, J= 8.6, J= 7.1, IH); 3.49 (dd, J= 9.8, J= 8.1, IH); 3.01 (dd, J= 9.8, J= 7.1, IH); 2.59 (dd, J= 16.8, J= 8.7, IH); 2.34 (m, IH); 2.08 (dd, J= 16.8, J= 7.9, IH); 1.95 (m, IH); 1.70 (m, IH); 1.47-1.28 (m, 4H); 0.91 (dt, J= 7.2, J= 2.1, 6H)

HPLC (GRAD 90/10) of compound (I) : retention time = 7.78 minutes

¹H NMR of compound (VII) (400 MHz, CDCl₃): δ = 6.14 (s, broad, IH); 5.27 (s, broad, IH); 4.43 (t app, J = 8.1, IH); 3.53 (t app, J = 9.1, IH); 3.01 (t app, J = 7.8, IH); 2.53 (dd, J = 16.5, J = 8.8, IH); 2.36 (m, IH); 2.14 (dd, J = 16.5, J = 8.1, IH); 1.97 (m, IH); 1.68 (m, IH); 1.43 (m, 2H); 1.34 (m, 2H); 0.92 (m, 6H)

3c. Epimerisation of compound of (2RV2-((R)-2-oxo-4-propyl-pyπOlidin-l-ylV butyramide (VID

Compound (VII) (200 mg, 0.94 mmol) is added to a solution of sodium tert- butoxide (20 mg, 10 % w/w) in isopropanol (2 mL) at room temperature. The reaction mixture is stirred at room temperature for 18h. The solvent is evaporated to afford 200 mg

(0.94 mmol, 100 %) of a white solid. Said white solid is a mixture of brivaracetam (I) and of (VII) in a ratio 49.3 / 50.7.

HPLC (ISO80): retention time= 7.45 min (49.3%) brivaracetam (I); retention time= 8.02 minutes (50.7%) compound (VII).

Route 2

Reference：ROUTE 2

1. WO2007031263A1 / US2009318708A1.

PATENT

http://www.google.com/patents/WO2007065634A1?cl=en

(scheme 3).

Scheme 3

scheme 4.

5h. Synthesis of brivaracetam and (V) A suspension of (Id) and (Ie) (0.6 g, 2.3 mmol) in MIBK (10 mL) is heated at

120°C for 6 hours. The resulting solution is concentrated and separated on chromatography column (Silicagel 600.068-0.200 mm, cyclohexane/EtOAc : 10/90) to give 0.13 g of brivaracetam (0.6 mmol, 26 %, ee = 94 %) and (V).

¹H NMR (400 MHz, CDCl₃): δ = 6.17 (s, broad, IH); 5.32 (s, broad, IH); 4.43 (dd, J= 8.6, J= 7.1, IH); 3.49 (dd, J= 9.8, J= 8.1, IH); 3.01 (dd, J= 9.8, J= 7.1, IH); 2.59 (dd, J= 16.8, J= 8.7, IH); 2.34 (m, IH); 2.08 (dd, J= 16.8, J= 7.9, IH); 1.95 (m, IH); 1.70 (m, IH); 1.47-1.28 (m, 4H); 0.91 (dt, J= 7.2,J= 2.1, 6H).

HPLC (method 90/10) : Retention time = 7.78 minutes Chiral HPLC : Retention time = 9.66 minutes (97%) MS (ESI): 213 MH⁺

Route 3

Reference：1. WO2007065634A1 / US2009012313A1.

PAPER

http://pubs.acs.org/doi/abs/10.1021/acs.oprd.6b00094

A Biocatalytic Route to the Novel Antiepileptic Drug Brivaracetam

Arnaud Schülé^*, Alain Merschaert, Christophe Szczepaniak, Christophe Maréchal, Nicolas Carly, John O’Rourke, and Célal Ates

Chemical Process Research and Development, Pharma Sciences, UCB Pharma S.A., Chemin du Foriest, 1420 Braine l’Alleud, Belgium

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00094

* E-mail: arnaud.schule@ucb.com; Telephone: +32.2.386.6208.

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References

von Rosenstiel P (Jan 2007). “Brivaracetam (UCB 34714)”. Neurotherapeutics 4 (1): 84–7. doi:10.1016/j.nurt.2006.11.004.PMID 17199019.
Malawska B, Kulig K (Jul 2005). “Brivaracetam UCB”. Current Opinion in Investigational Drugs 6 (7): 740–746. PMID 16044671.
Rogawski MA, Bazil CW (Jul 2008). “New molecular targets for antiepileptic drugs: alpha(2)delta, SV2A, and K(v)7/KCNQ/M potassium channels”. Current Neurology and Neuroscience Reports 8 (4): 345–352. doi:10.1007/s11910-008-0053-7. PMC 2587091.PMID 18590620.
Clinical trial number NCT00464269 for “Double-blind, Randomized Study Evaluating the Efficacy and Safety of Brivaracetam in Adults With Partial Onset Seizures” at ClinicalTrials.gov
Rogawski MA (Aug 2008). “Brivaracetam: a rational drug discovery success story”. British Journal of Pharmacology 154 (8): 1555–7.doi:10.1038/bjp.2008.221. PMC 2518467. PMID 18552880.
Matagne A, Margineanu DG, Kenda B, Michel P, Klitgaard H (Aug 2008). “Anti-convulsive and anti-epileptic properties of brivaracetam (ucb 34714), a high-affinity ligand for the synaptic vesicle protein, SV2A”. British Journal of Pharmacology 154 (8): 1662.doi:10.1038/bjp.2008.198. PMID 18500360.
http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/medicines/003898/human_med_001945.jsp&mid=WC0b01ac058001d124
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm486827.htm

Brivaracetam

Names

IUPAC name

(2S)-2-[(4R)-2-oxo- 4-propylpyrrolidin-1-yl] butanamide

Identifiers

Jmol interactive 3D

Properties

C₁₁H₂₀N₂O₂

212.15 g/mol

Pharmacology

ATC code

N03AX23

Legal status

Investigational

Routes of
administration

Oral

Nearly 100%

<20%

Hydrolysis, CYP2C8-mediated hydroxylation

Biological half-life

8 hrs

Excretion

>75% renal

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

//////BRIVARACETAM, UCB, 2016 FDA, UCB-34714

CCCC1CC(=O)N(C1)C(CC)C(=O)N

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2021260721&_cid=P12-KXX1JU-33531-1

Brivaracetam is chemically known as (2S)-2-[(4R)-2-oxo-4-propyltetrahydro-1H-pyrrol-1-yl] butanamide, having the chemical structure of formula 1 as below:

Brivaracetam is basically a chemical analogue of Levetiracetam, marketed under the brand name of BRIVIACT for the treatment as adjunctive therapy in the treatment of partial-onset seizures in patients at 16 years of age and older with epilepsy. Brivaracetam has an advantage over Levetiracetam in that it gets into the brain “much more quickly,” which means that “it could be used for status epilepticus, or acute seizures than cluster, or prolonged seizures”. From the Phase III trials, the self-reported rate of irritability with Brivaracetam was 2% for both drug doses (100 mg and 200 mg) vs 1% for placebo, which compares to as much as 10% for Levetiracetam in some post-marketing studies.

With the improved safety profile and possibility to be used for wider range of epilepsy, Brivaracetam is considered as one of the most promising 3^rd generation antiepileptic drugs.

Brivaracetam molecule is first disclosed in patent publication WO2001062726, which describes 2-oxo-1 -pyrrolidine derivatives and methods for their preparation. This patent publication further discloses compound (2S)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butanamide which is known under the international non propriety name as Brivaracetam. As per Biopharmaceutics Classification System, Brivaracetam is a class I drug (high solubility and permeability).

Some prior arts US6784197 and US7629474 disclose a process for synthesizing a diastereomeric mixture of (2S)-2-[(4R)-2-oxo-4-propylpyrrolidin-1-yl]-butanamide and (2S)-2-[(4S)-2-oxo-4-propylpyrrolidin-1-yl]-butanamide (Brivaracetam) which is purified by chiral HPLC (Scheme-I & Scheme-II respectively, as provided below). This process used for chiral resolution makes it difficult for bulk manufacturing as well as it affects the overall yield making the process uneconomical.

Scheme-I

Synthesis of (2S)-2-(2-oxo-4-propyl-1-pyrrolidinyl)butanamide

[As disclosed in columns 37-38 of US 6784197 B2]

Scheme-II

1.1 Synthesis of (2S)-2-aminobutyramide-Free base

1.2 Synthesis of 5-hydroxy-4-n-propylfuran-2-one

1.3 Synthesis of (2S)-2-((4R)-2-oxo-4-n-propyl-1-pyrrolidinyl)butanamide and

(2S)-2-((4S)-2-oxo-4-n-propyl-1-pyrrolidinyl)butanamide

[As disclosed in columns 6-7 of US 7629474 B2]

Moreover, some prior arts such as US7122682B2, US8076493B2, US8338621B2 and US8957226B2 also describe processes for preparing Brivaracetam, wherein, the purifications are reportedly done by chiral HPLC methods resulting into similar shortcomings.

Kenda et al.: Journal of Medicinal Chemistry, 2004, 47, 530-549 further proposes selection of (2S)-2-[(4R)-2-oxo-4-propylpyrrolidin-1-yl]butanamide 83α (ucb 34714; Brivaracetam) as the most interesting candidate showing 10 times more potency than Levetiracetam as an antiseizure agent in audiogenic seizure-prone mice. This article further discloses methods for synthesizing the said compound Brivaracetam. However, here too these compounds are synthesized as mixtures of stereoisomers (racemic or diastereoisomeric mixtures), separated by preparative HPLC on silica gel and/or chiral phases.

All these processes for the preparation of Brivaracetam as described in the above- mentioned prior arts suffer from many disadvantages which includes difficulty in achieving desired chiral purity, tedious and cumbersome work up procedures, high temperature and longer time reaction, multiple crystallizations or isolation steps, use of excess reagents and solvents, column chromatographic separations & purifications etc. All these disadvantages affect the overall yield as well as the quality of the final product Brivaracetam and intermediates produced thereof; further, rendering such processes to be uneconomical and unsuitable for industrial scale-ups.

As a result, enantioselective synthesis of Brivaracetam was perceived to be a possible way of overcoming such problems in view of the large-scale synthesis. However, very few prior arts have been found to report successful reduction of such concept into practice.

WO2016191435A1 (also as IN201717005820A) relates to a process for a scalable synthesis of enantiomerically pure Brivaracetam from an intermediate (4R)-4- Propyldihydrofuran-2(3H)-one (compound IV):

, wherein, R is saturated or unsaturated C1-20 alkyl or C1 alkyl-unsubstituted or substituted aryl, comprising the steps of decarboxylation of

the compound of formula IV

to produce the compound of formula VI

ring-opening of the compound of formula VI to produce the compound of formula VII

, wherein Rl is saturated or unsaturated Cl-20 alkyl or Cl alkyl-unsubstituted or substituted aryl; and X is CI Br I OMs, OTs, ONs; or

the compound of formula X
reacting the compound of formula VI with (S)-2- aminobutanamide or its salt to produce the compound of formula XII in one step; or reacting the compound of formula VI with alkyl (S)-2- aminobutanoate to produce Xll-a

, wherein R in the compound of formula Xll-a is a saturated or unsaturated C1-C20 alkoxyl; and then converting Xll-a to XII that is Brivaracetam by aminolysis and amide formation reaction.

In above mentioned prior arts, the synthesis of chiral lactone which is the key starting material for making Brivaracetam involved Grignard addition, column chromatography and Krapcho decarboxylation techniques at high temperature, all of which are not at all recommendable in view of process perspective at industrial levels. Further the final step of the said reaction often involved cryogenic condition –30°C which is also difficult with respect to industrial scale up activities.

Furthermore, prior art IN201641030239A disclosed a process for the preparation of Brivaracetam of Formula (I) by means of converting enantiomerically pure compound of Formula VII to obtain enantiomerically pure compound of Formula XI:

, wherein X is each independently selected from halogen; alkyl or aryl sulfonyloxy; OR2; R2 is optionally substituted C1-C12 alkyl, aryl, alkyl aryl, aryl alkyl;

such that the said process further comprises steps of:

1) cyclizing compound of formula VII to give enantiomerically pure compound of formula IX:

, wherein R2 is optionally substituted C1-C12 alkyl, aryl, alkyl aryl or aryl alkyl;

2) converting the compound of formula IX to give a enantiomerically pure compound of formula X:

, wherein X is halogen;

3) converting compound of formula X to give a enantiomerically pure compound of formula XI:

wherein X is each independently selected from halogen; alkyl or aryl sulfonyloxy; OR2; R2 as defined above; followed by 4) treating the enantiomerically pure compound of formula XI with (S)- aminobutyramide of formula XII or its salt thereof to obtain Brivaracetam of Formula I.

However, this process suffered from drawbacks of handling acid chloride. Acid chlorides are unstable and storing a large amount of acid chloride is also not recommendable in view of safety and stability in industries. Moreover, this prior art process involves use of HBr in acetic acid, where HBr liberates Br that is hazardous and not recommendable for industrial scale-up activities in view of safety and handling.

Some other prior arts such as CN108503573A, CN105646319A, CN106588740A, CN106588831A, CN108689903B and CN108929289A report various processes of synthesizing Brivaracetam from its lactone intermediate by various ring opening techniques. Among these, in particular CN108929289A discloses a process of reacting a compound represented by the formula IV with (S) -2-aminobutyramide in order to obtain Brivaracetam. The synthetic route is as follows:

Also, CN108689903B relates to a new preparation method of Brivaracetam that comprises steps of: a) subjecting a compound of formula III and (S) -2-aminobutanamide or salt thereof to condensation reaction, in the presence of a condensing agent, in order to obtain a compound shown in a formula IV, wherein the compound has two chiral centres; b) removal of the hydroxy-protecting group R1 to obtain a compound of formula V; and c) carrying out chlorination reaction on the compound shown in the formula V using a chlorination reagent to obtain a compound shown in the formula VI; and d) carrying out substitution reaction on the compound shown in the formula VI in the presence of an

alkaline reagent, and closing a ring to obtain Brivaracetam of formula I having two chiral centres.

It has further been noted that although the above reaction goes through formation of intermediates V and/or VI; however, these intermediates are not essentially formed from the key lactone intermediate of Brivaracetam that is (4R)-4-propyldihydrofuran-2(3H)-one [or (R)-lactone].

Furthermore, CN111196771A relates to a preparation method of Brivaracetam which comprises the steps of: 1) carrying out ring-opening reaction on a compound R-4-propyldihydrofuran-2-ketone in a formula II and a compound S-2-aminobutanamide in a formula III to obtain an intermediate compound in a formula I; 2) condensing the said intermediate compound of formula I is followed by cyclization to produce Brivaracetam

However, the ring-opening reaction in step 1 of this process essentially occurs under acidic conditions, specifically in presence of Lewis acids like tetra-isopropyl titanate, anhydrous aluminium trichloride, anhydrous zinc chloride, boron trifluoride diethyl etherate etc.; and also in presence of organic solvents chosen from one or more of anhydrous tetrahydrofuran, 2-methyltetrahydrofuran, acetone, dimethyl sulfoxide and N, N-dimethylformamide; which makes this process both industrially non-scalable and environmentally unfriendly.

The prior art Org. Process Res. Dev.2016. v 20. no 9. p 1566-1575 in its scheme 4, on page 17 also discloses a scheme for synthesizing Brivaracetam from its lactone intermediate:

Nevertheless, it has been noted that the process reported in this prior art provides Brivaracetam (API) with a very poor yield of ~30% and also having an inferior chiral purity of 95.9% ee, which does not even meet the ICH-specification for the Finished Product (API).

Furthermore, a recently filed patent application WO2020148787A1 (also as IN201931002041) recites a new, improved and economical process for enantioselective synthesis and purification of a key intermediate of Brivaracetam that is the R-lactone, essentially utilizing a low chiral loading and without involving any chiral chromatographic resolution technique. Even though this prior art also discloses a process for the preparation of a chirally pure Brivaracetam of formula I utilizing the said intermediate; however, that process is mostly a conventional one.

Accordingly, there is still a need in the art for a more economical and improved process for the synthesis of Brivaracetam with better purity and yield which overcomes the drawbacks of above prior arts.

Therefore, the present inventors have developed a cost effective, novel and efficient process for the preparation of Brivaracetam which essentially avoids all the drawbacks involved in prior art as mentioned above. The currently developed process is advantageously capable of producing the key lactone intermediate with more than 80% ee applying transfer hydrogenation with a very simple operation in view of process perspective. Further, by means of using such chiral lactone with more than 80% ee, the currently developed process is also capable of delivering >99.9% chirally pure Brivaracetam with excellent yield.

EXAMPLES:

EXAMPLE 1: Synthesis of (3R)-N-[(1S)-1-carbamoylpropyl]-3-(hydroxymethyl) hexanamide [Intermediate 7 of scheme A of the present invention]

Example 1 illustrates one pot process for preparing purified (3R)-N-[(1S)-1- carbamoylpropyl]-3-(hydroxymethyl) hexanamide [Intermediate 7] from Intermediate 3 (80% ee) as developed in step 1 of scheme A of the present invention.

Procedure:

In the first step of scheme A of the present invention, a mixture of (R)/(S)-4-propyldihydrofuran-2(3H)-one (Intermediate 3, R: S isomer = 80: 20) (1 eq), (S)-2-aminobutanamide (1.1 eq), triethylamine (1.5 eq) is refluxed at a temperature of 95±5 °C for 24h. The mixture is then cooled to 60-65 °C, washed with a mixture of dichloromethane and diisopropyl ether (2.5 vol) in order to get Intermediate-7 [(3R)-N-[(1S)-1-carbamoyl-propyl]-3-(hydroxymethyl) hexanamide] (80% yield).

Results:

Formation of Intermediate 7 is confirmed further by following analytical studies: a) The ¹H NMR analysis is conducted and the data as illustrated in accompanying figure 1 depicts: (400 MHz, DMSO-d₆): δ 0.6 (t, J= Hz, 6H), 1.07-1.18 (m, 1H), 1.21-1.35 (m, 3H), 1.45-1.43 (m, 1H), 1.61-1.72 (m, 1H), 1.75-1.90 (m, 1H), 2.03 (dd, J=6.64 & 14.08 Hz, 1H), 2.18 (dd, J=7.0 & 14.08 Hz, 1H), 3.28 (t, J=5.36 Hz, 2H), 4.07-4.18 (m, 1H), 4.43 (t, J=5.2 Hz, 1H), 6.95 (s, 1H), 7.28 (s, 1H), 7.76 (d, J=8.08 Hz, 1H).; thus, confirming formation of Intermediate 7 of the present invention.

b) The LCMS analysis is further conducted and the data as graphically illustrated in accompanying figure 2 provides a (M+H⁺) value of 231.0; thus, confirming formation of Intermediate 7 of the present invention.

c) The HPLC study is also conducted and the data as graphically illustrated in accompanying figure 3 confirms formation of Intermediate 7 of the present invention with chiral purity of 97.38%

EXAMPLE 2: Preparation of (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide [Intermediate 8A of scheme A of the present invention]: Example 2 illustrates a process for preparing (3R)-N-(1S)-1-Amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide [Intermediate 8A] from Intermediate 7 of example 1 above as developed in the present invention.

Procedure:

In second step of scheme A of the present invention, the said Intermediate 7 of example 1 above that is (3R)-N-(1S)-1-Amino-1-oxobutan-2-yl)-3-(hydroxymethyl) hexanamide (~98% Chemical purity and ~97% Chiral purity) (1736.86 mmol) is dissolved in DCM (1.2 L) at RT into a RBF under N₂ atm. Then the solution is cooled to 10-20 C and Oxaloyl chloride (2605.29 mmol) is added to this cooled solution at 10-20 °C. The mixture is stirred for 24 h at 25-40 °C under N₂ atm. Completion of the reaction is monitored by TLC. After completion of reaction, the solvent is distilled off and the residual mass is diluted with water (6 L), stirred at 30-50 °C for 4 h. Slurry mass is then filtered and washed with water (2×400 mL) followed by MTBE (800 mL). The solid is dried under vacuum at 50-55 °C for 4-5 h to afford Intermediate 8A that is (3R)-N-(1S)-1-Amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide as a white solid (92% yield).

Results:

Formation of Intermediate 8A is confirmed further by following analytical studies: a) The ¹H NMR analysis is conducted and the data as illustrated in accompanying figure 4 depicts: ¹H NMR (400 MHz, DMSO-d₆) : δ 0.83 (t, J=7.44 Hz, 3H), 0.85 (t, J=6.72 Hz, 3H), 1.20-1.40 (m, 4H), 1.43-1.56 (m, 1H), 2.08-2.18 (m, 1H), 2.20-2.28 (m, 2H), 3.61 (dd, J=4.6 & 10.8 Hz, 1 H), 3.67 (dd, J=4.6 & 10.8 Hz, 1H), 4.07-4.18 (m, 1H), 6.95 (s, 1H), 7.29 (s, 1H), 7.89 (d, J=8.12 Hz, 1H); thus confirming formation of Intermediate 8A of the present invention.

b) The LCMS analysis is further conducted and the data as graphically illustrated in accompanying figure 5 (a, b) provides a (M+H⁺) value of 249.20; thus, confirming formation of Intermediate 8A of the present invention.

EXAMPLE 3: Process for purification of Intermediate 8A forming Intermediate 8B Example 3 illustrates a process for purifying the said Intermediate 8A of example 2 above of the present invention.

Procedure:

The Intermediate 8A as obtained in example 2 above [that is (3R)-N-(1S)-1-Amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide] is first dissolved in a polar solvent like Acetonitrile raising the temperature to 50 to 60 °C; followed by stirring and then addition of another solvent methyl tert-butyl ether (MTBE) which is less polar in nature. The mixture is then cooled down to 0°C, the filtered mass thus obtained is dried in order to obtain a white solid of Intermediate 8B. The material thus obtained is further dissolved in THF (5 vol) at 60 °C, cooled to 20-30°C, followed by addition of heptane (5 vol), stirred at 10°C to 30 °C for 1 h. The mass obtained is filtered and washed with heptane (2×1 vol), dried under vacuum at 50-55°C in order to afford formation of purer form of Intermediate 8A that is Intermediate 8B that is (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide as a white solid having a chemical purity of 99.9% along with a chiral purity of 100% (yield: 390 g).

Results:

The purification of Intermediate 8A is further confirmed by the following analytical test results:

a) Chiral HPLC: A Chiral HPLC as illustrated in accompanying figure 6 confirmed formation of purest form of Intermediate 8B having 100% chiral purity [Peak 1; RT (min) = 6.244; %Area=100%].

b) GLP-HPLC: A GLP-HPLC as illustrated in accompanying figure 7 further confirmed formation of Intermediate 8B having 99.9% chemical purity [Peak 3; BRIV8; RT = 29.278; % Area=99.90%].

EXAMPLE 4: Synthesis of (3R)-N-[(1S)-1-carbamoylpropyl]-3-(hydroxymethyl) hexanamide [Intermediate 7’ of scheme B of the present invention]

Example 4 illustrates one pot process for preparing purified (3R)-N-[(1S)-1-carbamoylpropyl]-3-(hydroxymethyl) hexanamide [Intermediate 7’] from Intermediate 6 (99.99% ee) as developed in step-1 scheme B of the present invention.

Procedure:

In another method, in the first step of scheme B of the present invention, a mixture of (R)/(S)-4-propyldihydrofuran-2(3H)-one (Intermediate 6: S isomer = 99.99% : 0.1%) (1 eq), (S)-2-aminobutanamide (1.7 eq), triethylamine (5 eq) is refluxed at a temperature between 95±5 °C for 24 h. Then, the crude reaction mass is cooled and washed with dichloromethane and diisopropyl ether mixture (2.5 vol) in order to achieve Intermediate-7’ of scheme B of the present invention [(3R)-N-[(1S)-1-carbamoylpropyl]-3-(hydroxymethyl) hexanamide] (90% yield).

Results:

The chiral purity of the formed Intermediate 7’ is analyzed by HPLC method and the data as graphically illustrated in accompanying figure 8 confirms formation of Intermediate 7’ of the present invention with chiral purity of 99.11%

EXAMPLE 5: Preparation of (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide [Intermediate 8’ of scheme B of present invention]: Example 5 illustrates a process for preparing purest form of (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide [Intermediate 8’] from Intermediate 7’ of example 4 as developed in scheme B (step 2) of the present invention.

Procedure:

In the second step of scheme B of the present invention, the intermediate 7’ of the above example 4 that is (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(hydroxymethyl) hexanamide (98% Chemical purity and >99%Chiral purity) (1736.86 mmol) is dissolved in DCM (1.2 L) at RT in a round bottomed flask under N₂ atm. Then the solution is cooled to 10-30 °C and 1-Chloro-N,N,2-trimethyl-1-propenylamine (2605.29 mmol) is added to this cooled solution at 10-30 °C. The mixture is stirred for 24 h at 25-40 °C under N₂ atm. Completion of the reaction is monitored by TLC. After completion of the reaction, the solvent is distilled off and the residual mass is diluted with water (6 L), stirring at 30-50 °C for 4 h. The slurry mass thus obtained is then filtered and washed with water (2×400 mL) followed by methyl tert-buty ether (MTBE) (800 mL). The solid thus obtained is dried under vacuum at 50-55 °C for 4-5 h in order to afford formation of Intermediate 8’ that is (3R)-N-(1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide as a white solid (92% yield).

Results:

Formation of Intermediate 8’ is confirmed further by following analytical studies: a) The ¹H NMR analysis is conducted and the data as illustrated in accompanying figure 9 depicts: (400 MHz, DMSO-d₆): ¹H NMR (400 MHz, DMSO-d₆) : δ 0.83 (t, J=7.44 Hz, 3H), 0.85 (t, J=6.72 Hz, 3H), 1.20-1.40 (m, 4H), 1.43-1.56 (m, 1H), 2.08-2.18 (m, 1H), 2.20-2.28 (m, 2H), 3.61 (dd, J=4.6 & 10.8 Hz, 1 H), 3.67 (dd, J=4.6 & 10.8 Hz, 1H), 4.07-4.18 (m, 1H), 6.95 (s, 1H), 7.29 (s, 1H), 7.89 (d, J=8.12 Hz, 1H); thus, confirming formation of Intermediate 8’ of the present invention.

b) The LCMS analysis is further conducted and the data as graphically illustrated in accompanying figure 10 provides a (M+H⁺) value of 249.1; thus, confirming formation of Intermediate 8’ of the present invention.

c) The HPLC data as illustrated in accompanying figure 11 confirms 100% chiral purity of Intermediate 8’.

EXAMPLE 6: Preparation of (2S)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butanamide [Brivaracetam-API]:

Example 6 illustrates a process for preparing (2S)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butanamide [Brivaracetam API] from Intermediate 8B of example 3 or from Intermediate 8’ of example 5 as developed in step 3 of scheme A or scheme B of the present invention respectively.

Procedure:

In the final step of scheme A or scheme B of the present invention, the intermediate 8B of example 3 or intermediate 8’ of example 5 above that is (3R)-N-((1S)-1-Amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide (1608.04 mmol) is dissolved in dimethyl acetamide (0.5 vol) and isopropylacetate (2 L) into a RBF at 25-30 °C under N₂ atm. Then 18-Crown-6 (160.79 mmol) is added into the solution and stirred at RT for 30 min. Reaction mixture is then cooled to 0-10 °C and t-BuOK (1.5 eq) is added portion wise to the cooled solution over 1 h maintaining the temperature from – 0-10 °C to 25 °C under N₂ atm. Stirring is then continued for 2 h at -10 °C to 0 °C and then for 12 h at 15-25 °C under N₂ atm. Completion of reaction is monitored by TLC. After completion of reaction, the reaction mixture is quenched with addition of 1M HCl solution (pH~6.5-7.0). The resulting mixture is extracted with i-PrOAc (2 L) and MTBE (1 L). Water (0.5 L) is added to the combined organic extract and then filtered through celite bed, washed the bed with MTBE-i-PrOAc (1:1) (400 mL). The organic part is separated and the aqueous part is re-extracted with i-PrOAc-MTBE (1:1) (2 ×0.8 L). The combined organic phases are washed with brine solution (100 mL), dried over anhydrous Na₂SO₄, filtered and concentrated in vacuum under a rotary evaporator to afford crude API. Distillation of dimethylacetamide solvent from the crude is then done at high vacuum pressure (0.05 mm Hg) at 70 °C. Crude product is then dissolved in isopropyl acetate (1.6 L) and treated with activated charcoal (7% w/w) to afford a tech-grade crude of Brivaracetam API as a white solid (yield: 90%) with 97.82% chemical purity.

Results:

Formation of Brivaracetam API is confirmed further by following analytical studies: a) The ¹H NMR analysis is conducted and the data as illustrated in accompanying figure 12 depicts: ¹H NMR (400 MHz, DMSO-d₆) : δ 0.77 (t, J=7.32 Hz, 3H), 0.87 (t, J=7.2 Hz, 3H), 1.21-1.31 (m, 2H), 1.33-1.43 (m, 2H), 1.50-1.62 (m, 1H), 1.73-1.84 (m, 1H), 1.97 (dd, J=8.0 & 16.12 Hz, 1H), 2.18-2.28 (m, 1H), 2.37 (dd, J=8.4 & 16.14 Hz, 1H), 3.11 (dd, J=7.16 & 9.44 Hz, 1H), 3.36 (dd, J=9.2 & 17.5 Hz, 1H), 4.30 dd, J=5.44 & 10.28 Hz, 1H), 6.98 (s, 1H), 7.32 (s, 1H); thus, confirming formation of Brivaracetam API of the present invention.

b) The LCMS analysis is further conducted and the data as graphically illustrated in accompanying figure 13 provides a (M+H⁺) value of 213.0; thus, confirming formation of Brivaracetam API of the present invention.

^ Purification of Brivaracetam API:

The Brivaracetam thus formed above is further purified by means of dissolving the said material (307 g) in 30% i-PrOAc -MTBE (1 vol) at 55-60 °C, cool to 20-30°C. A mixture of Heptane and MTBE and DIPE (2:2:1) is added, stirred at 10 °C to 30°C for 1 h. The obtained mass is filtered and washed with heptane, which is subsequently dried under vacuum at 40-45 °C to afford (3R)-N-((1S)-1-amino-1-oxobutan-2-yl)-3-(chloromethyl) hexanamide as a white solid (yield: 80%, chiral purity 99.93% and chemical purity 99.94%).

Results:

a) Chiral HPLC: A Chiral HPLC as illustrated in accompanying figure 14 confirmed formation of purest form of Brivaracetam API having 99.93% chiral purity [Peak 2; RT (min) = 9.45; %Area=99.93%].

b) GLP-HPLC: A GLP-HPLC as illustrated in accompanying figure 15 further confirmed formation of Brivaracetam API having 99.9% chemical purity [Peak 2; RT = 21.138; % Area=99.94%].

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LAMIVUDINE

March 18, 2016 1:10 pm / Leave a comment

Lamivudine

CAS Registry Number: 134678-17-4

CAS Name: (2R-cis)-4-Amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-2(1H)-pyrimidinone

Additional Names: (-)-2¢-deoxy-3¢-thiacytidine; (-)-1-[(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cystosine; 3¢-thia-2¢,3¢-dideoxycytidine; 3TC

Manufacturers’ Codes: (-)-BCH-189; GR-109714X

Trademarks: Epivir (GSK); Zeffix (GSK)

Molecular Formula: C8H11N3O3S

Molecular Weight: 229.26

Percent Composition: C 41.91%, H 4.84%, N 18.33%, O 20.94%, S 13.99%

Properties: Crystals from boiling ethanol. mp 160-162°. [a]D21 -135° (c = 0.38 in methanol). Soly in water (20°): ~70 mg/ml.

Melting point: mp 160-162°

Optical Rotation: [a]D21 -135° (c = 0.38 in methanol)

Therap-Cat: Antiviral.

Keywords: Antiviral; Purines/Pyrimidinones; Reverse Transcriptase Inhibitor.

Lamivudine (2′,3′-dideoxy-3′-thiacytidine, commonly called 3TC) is an antiretroviral medication used to prevent and treat HIV/AIDS and used to treat chronic hepatitis B.^[1]

It is of the nucleoside analog reverse transcriptase inhibitor (NRTI) class. It is marketed in the United States under the tradenames Epivir and Epivir-HBV.

It is on the World Health Organization’s List of Essential Medicines, a list of the most important medication needed in a basic health system.^[2] As of 2015 the cost for a typical month of medication in the United States is more than 200 USD.^[3]

Medical uses

Lamivudine has been used for treatment of chronic hepatitis B at a lower dose than for treatment of HIV/AIDS. It improves the seroconversion of e-antigen positive hepatitis B and also improves histology staging of the liver. Long term use of lamivudine leads to emergence of a resistant hepatitis B virus (YMDD) mutant. Despite this, lamivudine is still used widely as it is well tolerated.

Resistance

Mechanism of action

Lamivudine is an analogue of cytidine. It can inhibit both types (1 and 2) of HIV reverse transcriptase and also the reverse transcriptase of hepatitis B virus. It is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3′-OH group in the incorporated nucleoside analogue prevents the formation of the 5′ to 3′ phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated.

Lamivudine is administered orally, and it is rapidly absorbed with a bio-availability of over 80%. Some research suggests that lamivudine can cross the blood–brain barrier. Lamivudine is often given in combination with zidovudine, with which it is highly synergistic. Lamivudine treatment has been shown to restore zidovudine sensitivity of previously resistant HIV. Lamivudine showed no evidence of carcinogenicity or mutagenicity in in vivo studies in mice and rats at doses from 10 to 58 times those used in humans.^[7]

History

Racemic BCH-189 (the minus form is known as Lamivudine) was invented by Dr. Bernard Belleau while at work at McGill University and Dr Paul Nguyen-Ba at the Montreal-based IAF BioChem International, Inc. laboratories in 1988 and the minus enantiomer isolated in 1989. Samples were first sent to Dr. Yung-Chi Cheng of Yale University for study of its toxicity. When used in combination with AZT, he discovered that Lamivudine’s negative form reduced side effects and increased the drug’s efficiency at inhibiting reverse transcriptase.^[8] The combination of Lamivudine and AZT increased the efficiency at inhibiting an enzyme HIV uses to reproduce its genetic material. As a result, Lamivudine was identified as a less toxic agent to mitochondria DNA than other retroviral drugs.^[9]

Lamivudine was approved by the Food and Drug Administration (FDA) on November 17, 1995 for use with zidovudine (AZT) and again in 2002 as a once-a-day dosed medication. The fifth antiretroviral drug on the market, it was the last NRTI for three years while the approval process switched to protease inhibitors. According to the manufacturer’s 2004 annual report, its patent will expire in the United States in 2010 and in Europe in 2011.

On September 2014, Dr. Gorbee Logan, a Liberian physician, reported positive results while treating Ebola virus disease with Lamivudine. Out of 15 patients treated with the antiviral, 13 (those treated within the third to fifth day of symptoms being manifested) survived the disease and were declared virus-free; the remaining cases (treated from the fifth day or later) died.^[10]^[11]

Presentation

Epivir 150 mg or 300 mg tablets (GlaxoSmithKline; US and UK) for the treatment of HIV;
Epivir-HBV 100 mg tablets (GlaxoSmithKline; US only) for the treatment of hepatitis B;
Zeffix 100 mg tablets (GlaxoSmithKline; UK only) for the treatment of hepatitis B.
3TC 150 mg tablets (GlaxoSmithKline; South Africa) for the treatment of HIV;

Lamivudine is also available in fixed combinations with other HIV drugs:

Lamivudine (I) (CAS No. 134678-17-4) is chemically known as (-)-[2R,5S]-4_T amino- 1 – [2-(hydroxymethyl)- 1 ,3 -oxathiolan-5-yl] -2( 1 H)-pyrimidin-2-one.

Formula (I)

Lamivudine is a reverse transcriptase inhibitor used alone or in combination with other classes of Anti-HIV drugs in the treatment of HIV infection. It is available commercially as a pharmaceutical composition under the brand name EPIVIR^®, marketed by GlaxoSmithKline, and is covered under US 5,047,407.

This molecule has two stereo-centres, thus giving rise to four stereoisomers: (±)- Cis Lamivudine and (±)-Trans Lamivudine. The pharmaceutically active isomer however is the (-)-Cis isomer which has the absolute configuration [2R,5S] as show in Formula (I).

US 5,047,407 discloses the 1,3-oxathiolane derivatives; their geometric (cis/trans) and optical isomers. This patent describes the preparation of Lamivudine as a mixture of cis and trans isomers (shown in scheme I). The diastereomers obtained are converted into N-acetyl derivatives before separation by column chromatography using ethylacetate and methanol (99:1); however, this patent remains silent about further resolution of the cis isomer to the desired (-)- [2R,5S]-Cis-Lamivudine. Secondly, as the ethoxy group is a poor leaving group, the condensation of cytosine with compound VI gives a poor yield, i.e. 30 – 40%, of compound VII. Thirdly, chromatographic separation that has been achieved only after acetylation requires a further step of de-acetylation of the cis-(±)- isomer. Also, separation of large volumes of a compound by column chromatography makes the process undesirable on a commercial scale.

(+/-) Cis (+/-) Cis Lamivudine (VIII)

Scheme – 1 Efforts have been made in the past to overcome the shortcomings of low yield and enantiomeric enrichment, hi general, there have been two approaches to synthesize (— )-[2R,5S]-Cis-Lamivudine. One approach involves stereoselective synthesis, some examples of which are discussed below.

US 5,248,776 describes an asymmetric process for the synthesis of enantiomerically pure β-L-(-)-l,3-oxathiolone-nucleosides starting from optically pure 1,6-thioanhydro-L-gulose, which in turn can be easily prepared from L- Gulose. The condensation of the 1,3-oxathiolane derivative with the heterocyclic base is carried out in the presence of a Lewis acid, most preferably SnCl_4, to give the [2R,5R] and [2R,5S] diastereomers that are then separated chromatographically.

US 5,756,706 relates a process where compound A is esterified and reduced to compound B. The hydroxy group is then converted to a leaving group (like acetyl) and the cis- and trans-2R-tetrahydrofuran derivatives are treated with a pyrimidine base, like N-acetylcytosine, in the presence trimethylsilyl triflate to give compound C in the diastereomeric ratio 4: 1 of cis and trans isomers.

A B C

Z = S₅ CH

Dissolving compound C in a mixture of 3:7 ethyl acetate-hexane separates the cis isomer. The product containing predominantly the cis-2R,5S isomer and some trans-2R,5R compound is reduced with NaBH₄ and subjected to column chromatography (30% MeOH-EtOAc) to yield the below compound.

US 6,175,008 describes the preparation of Lamivudine by reacting mercaptoacetaldehyde dimer with glyoxalate and further with silylated pyrimidine base to give mainly the cis-isomer by using an appropriate Lewis acid, like TMS-

I₅ TMS-Tf, TiCl₄ et cetera. However the stereoselectivity is not absolute and although the cis isomer is obtained in excess, this process still requires its separation from the trans isomer. The separation of the diastereomers Js done by acetylation and chromatographic separation followed by deacetylation. Further separation of the enantiomers of the cis-isomer is not mentioned.

US 6,939,965 discloses the glycosylation of 5-fluoro-cytosine with compound F (configuration: 2R and 2S)

. F

The glycosylation is carried out in the presence of TiCl₃(OiPr) which is stereoselective and the cis-2R,5S-isomer is obtained in excess over the trans- 2S,5S-isomer. These diastereomers are then separated by fractional crystallization.

US 6,600,044 relates a method for converting the undesired trans-l,3-oxathiolane nucleoside to the desired cis isomer by a method of anomerizatioή or transglycosylation and the separation of the hydroxy-protected form of cis-, trans- (-)-nucleosides by fractional crystallization of their hydrochloride, hydrobromide, methanesulfonate salts. However, these cis-trans isomers already bear the [R] configuration at C2 and only differ in their configuration at C5; i.e. the isomers are [2R,5R] and [2R,5S]. Hence diastereomeric separation directly yields the desired [2R, 5S] enantiomer of Lamivudine.

In the second approach to prepare enantiomerically pure Lamivudine the resolution of racemic mixtures of nucleosides is carried out. US 5,728,575 provides one such method by using enzyme-mediated enantioselective hydrolysis of esters of the formula

wherein, ‘R’ is an acyl group and ‘Rl ‘ represents the purine or pyrimidine base.

‘R’ may be alkyl carboxylic, substituted alkyl carboxylic and preferably an acyl group that is significantly electron-withdrawing, eg. α-haloesters. After selective hydrolysis, the process involves further separation of the unhydrolyzed ester from the^‘ enantiomerically pure 1,3-oxathiolane-nucleoside. Three methods are suggested in this patent, which are:

1. Separation of the more lipophilic unhydrolyzed ester by solvent extraction with one of a wide variety of nonpolar organic solvents.

2. Lyophilization followed by extraction into MeOH or EtOH. 3. Using an HPLC column designed for chiral separations.

In another of its aspects, this patent also refers to the use of the enzyme cytidine- deoxycytidine deaminase, which is enantiomer-specific, Λo catalyze the deamination of the cytosine moiety and thereby converting it to uridine. Thus, the enantiomer that remains unreacted is still basic and can be extracted by using an acidic solution.

However, the above methods suffer from the following drawbacks, (a) Enzymatic hydrolysis sets down limitations on choice of solvents: alcohol solvents cannot be used as they denature enzymes. (b) Lyophilization on an industrial scale is tedious, (c) Chiral column chromatographic separations are expensive.

WO 2006/096954 describes the separation of protected or unprotected enantiomers of the cis nucleosides of below formula by using a chiral acid to form diastereomeric salts that are isolated by filtration. Some of the acids used are R-

(-)-Camphorsulfonic acid, L-(-)-Tartaric acid, L-(-)-Malic acid, et cetera.

However, the configuration of these CIS-nucleosides are [2R,4R] and [2S,4S] as the heterocyclic base is attached at the 4 position of the oxathiolane ring and the overall stereo-structure of the molecule changes from that of the 2,5-substituted oxathiolane ring.

Thus various methods are described for the preparation of Lamivudine. However there is no mention in the prior art about the separation of an enantiomeric pair, either cis-(±) or trans-(±), from a mixture containing cis-[2R,5S], [2S,5R] and trans-[2R,5R], [2S,5S] isomers. Further, there also is a need to provide resolution of the cis-(±) isomers to yield the desired enantiomer in high optical purity.

CN 1223262 (Deng et aϊ) teaches the resolution of a certain class of compounds called Prazoles by using chiral host compounds such as dinaphthalenephenols (BINOL), diphenanthrenols or tartaric acid derivatives. The method consists of the formation of a 1:1 complex between the chiral host (BINOL) and one of the enantiomers, the guest molecule. The other enantiomer remains in solution. (S)- Omeprazole, which is pharmaceutically active as a highly potent inhibitor of gastric acid secretion, has been isolated from its racemic mixture in this manner by using S-BINOL.

BINOL is a versatile chiral ligand that has found its uses in various reactions involving asymmetric synthesis (Noyori, R. Asymmetric Catalysis in Organic

Synthesis) and optical resolution (Cram, D. J. et al J. Org. Chem. 1977, 42, 4173-

4184). Some of these reactions include BINOL-mediated oxidation and reduction reactions, C-C bond formation reactions such as Aldol reaction, Michael addition,

Mannich reaction et cetera (Brunei Chem. Rev. 2005 105, 857-897) and kinetic resolution, resolution by inclusion complexation et cetera.

BINOL, or l,l’-bi-2-Naphthol, being an atropoisomer possesses the property of chiral recognition towards appropriate compounds. One of the uses of BINOL in resolution that is known in literature is in Host-Guest complexation. In one such example, 1,1-binaphthyl derivatives have been successfully incorporated into optically active crown ethers for the enantioselective complexation of amino acid esters and chiral primary ammonium ions (Cram, D. J. Ace. Chem. Res. 1978, 11, 8-14). The chiral ‘host’ is thus able to discriminate between enantiomeric compounds by the formation of hydrogen bonds between the ether oxygen and the enantiomers. The complex formed with one of the isomers, the ‘guest’, will be less stable on steric grounds and this forms the basis for its separation.

It is evident from the literature cited that there exists a need to (a) synthesize Lamivudine by a process requiring less expensive, less hazardous and easily available reagents, and (b) achieve good yields with superior quality of product without resorting to column chromatography as a means of separation, thereby making the process of Lamivudine manufacture more acceptable industrially.

CLIP

ideally, the chemical synthesis of APIs begins from simple, inexpensive building blocks or RMs that are used for multiple purposes and are available in the fine chemicals industry, though some require uncommon RMs that contribute significantly to API manufacturing cost. RMs are converted into APIs by multi-step processes of breaking old chemical bonds and making new ones. A synthesis of 3TC is shown in . In the seven-step sequence, six steps involve breaking existing chemical bonds and creating new ones to build the molecular architecture of the API. The final recrystallization of an API is a critical step; at this stage the crystalline form of the API is determined and related substances (impurities) are removed or reduced to acceptable levels. APIs are often milled in a final step so that their particle size distribution (PSD) falls within specified limits. The crystalline form and PSD of an API must be controlled, because these properties are often critical to the formulation, dissolution, absorption and bioavailability of a drug. Bioavailability is the fraction of a drug dose that reaches systemic circulation (that is, is present in blood plasma) after administration. By definition, a drug is 100% bioavailable when administered by injection; drugs for ART are taken every day and administration by injection is not possible.

The cost of ART is absolutely critical to ensuring access in LMICs. The cost of manufacturing an API is dependent upon the cost of RMs, the cost of overheads and labour (OHL) and volume demand for the product. OHL includes the capital investment to build a manufacturing facility and operating costs, including personnel and energy, waste disposal and the eventual cost of decommissioning of the facility. Increased volume demand generally decreases the cost contribution of RM and OHL. Substantial production volumes are required to obtain full economy of scale . Producing 1–5 metric tons per year is substantially more expensive per kilogram than producing 100 metric tons of an API. There is a practical limit of approximately 50–100 metric tons/year beyond which cost reductions are modest with increased volume, but this practical limit refers to the volumes of drug manufactured in any single manufacturing plant. Exceptions to these generalizations do occur, most often when demand exceeds either the existing manufacturing capacity for a specific API or the availability of critical RMs . Exceptions that have occurred include shortages of β-thymidine for producing AZT and a squeeze on the availability and price of adenine as a starting material for TDF. Another contributor to RM and OHL costs is the efficiency of a chemical synthesis. Since operating costs for a manufacturing facility may be USD2,000/h, the number of steps or processing time for a chemical synthesis affects manufacturing cost. The efficiency of a synthesis is often quoted as an E-factor representing the kilograms of waste produced per kilogram of product manufactured. Waste management is expensive in chemical manufacturing wherever environmental guidelines are both reasonable and followed. From a slightly different perspective, increasing the overall yield of an API synthesis reduces RM use and associated cost for manufacturing.

Jinliang L, Feng LV. inventors; Shanghai Desano Pharmaceutical, assignee. A process for stereoselective synthesis of lamivudine. European Patent Application EP 2161 267 A1. 2007 June 29.

3. US Food and Drug Administration. United States Code of Federal Regulations Title 21, subpart B: procedures for determining the bioavailability or bioequivalence of drug products. (Updated 6 January 2014. Accessed 20 May 2014.) Available from http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?CFRPart=320

4. Pollak P, Badrot A, Dach R. API manufacturing: facts and fiction. Have costs of Chinese and Indian fine chemical producers closed in on European and US levels? (Updated 23 January 2012. Accessed 20 May 2014.) Available from http://www.contractpharma.com/issues/2012-01/view_features/api-manufacturing-facts-and-fiction/

5. Daiichi Sankyo Europe Gmb H. Priority projects in research and development. (Updated 20 May 2014. Accessed 24 May 2014.) Available from http://www.daiichi-sankyo.eu/research-development/priority-projects.html

6. Sheldon RA. The E-factor, fifteen years on. Green Chem 2007; 9:1273-1283. doi:10.1039/b713736m

PATENT

http://www.google.com/patents/EP2086955A2?cl=en

Object of the invention

Thus, one object of the present invention is to provide a process for the synthesis of_Lamivudine which is cost effective, uses less hazardous and easily available reagents, yet achieves good yields with superior quality of product without resorting to column chromatography.

A further object of the present invention is to provide an improved process for the synthesis of Lamivudine, by separating the mixture of diastereomers: Cis-[2R,5S], [2S,5R] from Trans-[2R,5R], [2S,5S] and then resolving the Cis isomers using BINOL to obtain (-)-[2R,5S]^Cis-Lamivudine with at least 99% ee.

This 1,3-oxathiolane compound VIII is further condensed with silylated cytosine in the presence of a Lewis acid such as trimethylsilyliodide to get protected 6-amino-3 – {2-hydroxymethyl- 1 ,3 -oxathiolan-5-yl} -3 -hydropyrimidine- 2-one (compound IX). OH

Cis(±)and Trans (±) racemic mixtures

Lamivudine (-)-[2

Compound (IX) is mixture of following optical isomers

SCHEME 2 The separation of the four-component diastereomeric mixture of isomers bearing the following configuration: trans-[2R,5R], [2S.5S] and cis-[2R,5S], [2S,5R] forms the next step. The separation efficiency of the benzoyl-protected compound

Example 9

Preparation of Lamivudine: (-)-[2R,5S]-4-amino-l-[2-(hydroxymethyl)-l,3- oxathiolan-5 -yl] -2(1 H)-pyrimidin-2-one

Compound I 5mL of cone. HCl was slowly added to a solution of 2Og of Lamivudine-BINOL complex in 100ml of ethylacetate and 10OmL of DM water (pH 2-2.5). The layers. were separated and a 10OmL aliquot of ethylacetate was added to the aqueous layer. The layers were separated again and the aqueous layer was neutralized using 1OmL of 10% aqueous NaOH solution. The solvent was recovered under vacuum at 40-45 ⁰C, the product obtained was dissolved in 160 mL of methanol, filtered, the filtrate was concentrated and 32 mL of water-ethanol mixture (3:1) was added to this product, heated to get a clear solution, cooled to 5 – 10 ⁰C and then filtered. The residue was vacuum dried at 45-50 ⁰C. Yield: 4-5g.

Enantiomeric excess = 99.74 % m.p. = 133-135 °C [<X]_D at 25°C = 98.32° (c = 5 water)

¹H NMR (DMSO d₆): 2.99-3.07 (dd, IH), 3.35-3.38 (dd, IH), 3.72-3.74 (m, 2H), 5.14-5.18 (t, IH), 5.32-5.38 (t, IH), 5.71-5.75 (d, IH), 6.16-6.21 (t, IH), 7.22-

7.27 (d, 2H), 7.80-7.83 (d, IH)

Moisture content: 1.67%

IR (in KBr, cm^“1): 3551, 3236, 2927, 1614, 1492, 1404, 1336, 1253, 1146, 1052,

967, 786. MS: M+l =230

XRD [2Θ] (Cu – K_a1=I.54060A, K_a2=1.54443A K_β= 1.39225A; 4OmA, 45kV):

5.08, 9.89, 10.16, 11.40, 11.65, 12.96, 13.23, 15.26, 15.82, 17.74, 18.74, 18.88,

19.67, 20.69, 22.13, 22.88, 23.71, 25.47, 26.07.

PATENT

http://www.google.com/patents/WO2013021290A1?cl=en

PAPER

http://pubs.rsc.org/en/content/articlehtml/2013/cc/c3cc45551c

CLIPS

EP 0382526; EP 0711771; JP 1996119967; JP 2000143662; US 5047407

There are two options for the synthesis of lamivudine: In the first approach the intact nucleoside analogue is prepared in racemic form by resolution to afford the required chiral product. This can be effected by an enzyme-mediated enantiospecific reaction. In the second approach synthesis of a chiral sugar component precedes coupling with the cytosine base under conditions where the chirality of the sugar precursor is maintained. The first approach is outlined in Scheme 18435601a. The oxathiolane (III) is obtained as a 1:1 mixture of anomers from reaction of benzoyloxyacetaldehyde (I) with mercaptoacetaldehyde dimethylacetal (II) in the presence of a Lewis acid. Treatment of (III) with silylated cytosine (IV) in the presence of TMS-triflate affords a 1:1 mixture of beta- and alpha-anomers (V) from which the required beta-anomer may be obtained by crystallization. Various alternative coupling conditions have been reported which yield almost exclusively the beta-anomer, notably as a result of the use of SnCl4. Subsequent deprotection affords the racemic nucleoside (VI) (BCH189). The resolution may be effected by a variety of enzymatic processes. Treatment of the nucleoside with phosphorus oxychloride and trimethylphosphate affords the 5′-monophosphate (VII). The natural enantiomer is selectively recognized by the 5′-nucleotidase from Crotalus atrox venom to afford the (+)-beta-D-nucleoside (VIII) and leave the unatural (-)-beta-L-enantiomer as the monophosphate (IX). Facile separation of these two products and subsequent dephosphorylation of (IX) using bacterial alkaline phosphatase affords lamivudine. Selective enzymatic recognition of the natural enantiomer may also be used to advantage in the resolution using cytidine deaminase derived from E. coli. In this case the enzyme is responsible for enantiospecific hydrolysis of the natural form to afford a readily separable mixture of lamivudine and the uridine derivative (X). Other enzymes including esterases and phosphodiesterases have application in the resolution of derivatives of the racemic nucleoside.

J Org Chem 1992,57(8),2217-9

The second general approach to synthesis of lamivudine does not involve intermediacy of the racemic nucleoside. A variety of routes are available for preparing chiral oxathiolane intermediates which may be coupled to the cytosine base under appropriate conditions where the chirality of the oxathiolane is maintained. Various natural carbohydrate precursors have utility in the synthesis of lamivudine; for example, a synthesis from L-gulose has recently been reported. (+)-Thiolactic acid (XI) has served as a starting material for chiral oxathiolane (XII), which is coupled to silylated cytosine in the presence of TMS-iodide to afford (XIII). Separation of the pure beta-anomer and deprotection affords lamivudine. Alternatively, racemic acid (XV) may be prepared from glyoxylic acid (XIV) and resolution using a suitable chiral base such as norephedrine would afford the chiral acid (XVI), which may be esterified prior to coupling with cytosine to give (XVII) followed by final reduction to lamivudine.

PATENT

http://www.google.com/patents/EP2161267A1?cl=en

Lamivudine is a nucleoside reverse transcriptase inhibitor, and is a kind of deoxycytidine analogue, which can inhibit the reproduction of Human immunodeficiency virus (HIV) and hepatitis B virus (HBV), whose chemical name is (2R-cis)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-1H-pyrimidin-2-one, and structural formula is as follows:

In 1990, Belleau et al firstly reported Lamivudine structure, and BioChem Pharma of Canada firstly developed Lamivudine to be used to treat AIDS ( WO91/17159 ) and hepatitis B ( EP0474119 ), and found that it had distinguished therapeutic effect on hepatitis B. Since Lamivudine has two chiral centers, it has 4 stereisomers, among which the 2R,5S (2R–cis)-isomer is the most potent in anti-HIV and anti-HBV activities, and its cytotoxicity on some cells is lower than its enatiomer or racemic body.
WO94/14802 mentioned two synthetic schemes (see Scheme 1 and Scheme 2):
In the above two schemes of this process, chirality was not controlled, and the final product was obtained by column chromatography, thus the yield was low and the requirement on the equipment was high, resulting in that the production cost was high and the operation in the production could not be controlled easily.

The specific reaction scheme is as follows:

synthetic route is preferably as follows:

. The specific reaction scheme is as follows:

The specific reaction scheme is as follows:

Example 8 The preparation of (2R,5S)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolane-5-yl) -2(1H)-pyrimidone (Lamivudine)

The compound of Example 7 (41.0g, 0.1mol) and methanol (250ml) were added to a reaction flask, and then stirred to make the compound dissolved in methanol. The mixture was cooled to 0 °C, and then K₂CO₃ (41.2g, 0.3mol) was added. The mixture was further stirred at room temperature overnight and then was adjusted by 0.1N HCl to a pH of about 7. The mixture was filtered and the solvent was evaporated under reduced pressure from the filtrate, and then to the residue was added 150ml of water. The aqueous layer was extracted by 150ml of toluene (50ml X 3), and then p-nitrobenzoic acid (16.8g, 0.1mol) was added to the aqueous layer and refluxed for 30 minutes, after which, the reaction mixture was cooled and further stirred at 0-5 °C for 2 hours. Then the reaction mixture was filtered and dried to give 31.7g of a white solid.
The resulting salt and anhydrous ethanol (120ml) were added to a reaction flask, and warmed to 70-75 °C. Triethylamine (12ml) was added dropwise, and the reaction was conducted at that temperature for 2 hours. Then the mixture was cooled to 50 °C, at which point ethyl acetate (150ml) was added dropwsie. After the addition was complete, the mixture was cooled to 10 °C and further stirred for 4 hours. The mixture was filtered to give 15.6g of Lamivudine, and the yield was 68%. 1H-NMR (DMSO-d6) δ: 7.83(dd, 1H), 7.17∼7.23(dd, 2H), 6.21(t, 1H), 5.72 (dd, 1H), 5.29 (t, 2H), 5.16 (t, 1H), 3.70∼3.74 (m, 2H), 3.32∼3.43 (dd, 1H), 3.01∼3.05(dd, 1H); Elemental analysis: C8H11N3O3S found(%): C 41.85, H 4.88 N 18.25, S 13.94; calculated (%) C 41.91, H 4.84, N 18.33, S13.99.

PAPER

http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-9-265

References

1″Lamivudine”. The American Society of Health-System Pharmacists. Retrieved 31 July 2015.
2
“WHO Model List of EssentialMedicines” (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
3
Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 65. ISBN 9781284057560.
4
Fox Z, Dragsted UB, Gerstoft J, et al. (2006). “A randomized trial to evaluate continuation versus discontinuation of lamivudine in individuals failing a lamivudine-containing regimen: The COLATE trial”. Antiviral Therapy 11 (6): 761–70. PMID 17310820.
5
http://hivdb.stanford.edu/index.html Stanford University Drug Resistance Database.
6
Koziel MJ, Peters MG (2007). “Viral hepatitis in HIV infection”. N Engl J Med 356 (14): 1445–54. doi:10.1056/NEJMra065142. PMID 17409326.
7
“Epivir package insert” (PDF). GlaxoSmithKline. Retrieved January 20, 2011.
8
Curtis, John (June 20, 1998). “Hunting Down HIV”. Yale Medicine.
9
Soderstrom, E John (July 10, 2003). “National Institutes of Health: Moving Research from the Bench to the Bedside”.
10
Cohen, Elizabeth (September 29, 2014). “Doctor treats Ebola with HIV drug in Liberia — seemingly successfully”. CNN.
11 HIV drug may stop Ebola. Operonlabs.com, 27 September 2014

Literature References: Reverse transcriptase inhibitor. Prepn: J. A. V. Coates et al., WO 9117159 C.A. 117, 111989 (1991). Synthesis of enantiomers: J. W. Beach et al., J. Org. Chem. 57, 2217 (1992); of (-)-enantiomer: D. C. Humber et al., Tetrahedron Lett. 33, 4625 (1992). HPLC determn in urine: D. M. Morris, K. Selinger, J. Pharm. Biomed. Anal. 12, 255 (1994). Clinical trial in hepatitis B: F. Nevens et al., Gastroenterology 113, 1258 (1997). Review of pharmacology and clinical efficacy in HIV infection: C. M. Perry, D. Faulds, Drugs 53, 657-680 (1997).

External links

Epivir (manufacturer’s website)

Lamivudine
Systematic (IUPAC) name


4-amino-1-[(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-1,2-dihydropyrimidin-2-one
Clinical data
Trade names	Epivir
AHFS/Drugs.com	monograph
MedlinePlus	a696011
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Routes of administration	Oral
Legal status
Legal status	UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	86%
Protein binding	Less than 36%
Biological half-life	5 to 7 hours
Excretion	Renal (circa 70%)
Identifiers
CAS Number	134678-17-4
ATC code	J05AF05 (WHO)
PubChem	CID 73339
DrugBank	DB00709
ChemSpider	66068
UNII	2T8Q726O95
KEGG	D00353
ChEMBL	CHEMBL141
NIAID ChemDB	000388
Synonyms	L-2′,3′-dideoxy-3′-thiacytidine
PDB ligand ID	3TC (PDBe, RCSB PDB)
Chemical data
Formula	C₈H₁₁N₃O₃S
Molar mass	229.26 g/mol

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New FDA Guidance on Completeness Assessements for Type II API Drug Master Files

March 17, 2016 10:17 am / Leave a comment

DRUG REGULATORY AFFAIRS INTERNATIONAL

Since 1st October 2012, special regulations have been applying to the US Type II Drug Master Files. This year in February, the FDA published a new Guidance for Industry. Read here what the DMF holder has to consider when submitting data about the API Drug Master File.

http://www.gmp-compliance.org/enews_05256_New-FDA-Guidance-on-Completeness-Assessements-for-Type-II-API-Drug-Master-Files_15328,15339,S-WKS_n.html

Since the coming into force of the “Generic Drug User Fee Act” (GDUFA) on 1st October 2012, special regulations have been applying to the submission to the FDA of a Drug Master Files for a pharmaceutical API (Type II DMF). The DMF holder must pay a one-time fee when authorising the reference of his/ her DMF in an application for a generic drug (Abbreviated New Drug Application, ANDA). Moreover, the DMF will undergo a completeness assessment through the FDA.

This year in February, the FDA published a Guidance for Industry entitled “Completeness Assessments for Type II API DMFs under GDUFA”…

View original post 350 more words

Zydus Chairman and Managing Director,Mr. Pankaj R. Patel won the prestigious ‘Gujarat Business Leader of the Year’ award at the CNBC Bajar, Gujarat Ratna Awards 2015-16

March 14, 2016 3:38 am / 1 Comment on Zydus Chairman and Managing Director,Mr. Pankaj R. Patel won the prestigious ‘Gujarat Business Leader of the Year’ award at the CNBC Bajar, Gujarat Ratna Awards 2015-16

Zydus Group

Zydus Chairman and Managing Director,Mr. Pankaj R. Patel won the prestigious ‘Gujarat Business Leader of the Year’ award at the CNBC Bajar, Gujarat Ratna Awards 2015-16 from Hon’ble Chief Minister of Gujarat, Smt. Anandiben Patel at a glittering ceremony held at Hyatt, Ahmedabad.

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The specific reaction scheme is as follows:

synthetic route is preferably as follows:

. The specific reaction scheme is as follows:

The specific reaction scheme is as follows:

Example 8 The preparation of (2R,5S)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolane-5-yl) -2(1H)-pyrimidone (Lamivudine)

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