Invention Grant
- Patent Title: Preparation of Zopiclone and its enantiomerically enriched isomer
- Patent Title (中): 佐匹克隆及其对映体富集异构体的制备
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Application No.: US12595663Application Date: 2008-04-10
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Publication No.: US08309723B2Publication Date: 2012-11-13
- Inventor: Om Dutt Tyagi , Tushar Kumar Srivastava , Vellanki Siva Ram Prasad , Dnyandev Ragho Rane , Bandi Naga Durga Rao , Daggula Srinivas Reddy
- Applicant: Om Dutt Tyagi , Tushar Kumar Srivastava , Vellanki Siva Ram Prasad , Dnyandev Ragho Rane , Bandi Naga Durga Rao , Daggula Srinivas Reddy
- Applicant Address: IN Hyderabad
- Assignee: Mylan Laboratories Ltd.
- Current Assignee: Mylan Laboratories Ltd.
- Current Assignee Address: IN Hyderabad
- Agency: Ladas & Parry LLP
- Priority: IN782/CHE/2007 20070412
- International Application: PCT/IN2008/000239 WO 20080410
- International Announcement: WO2008/126105 WO 20081023
- Main IPC: C07D495/00
- IPC: C07D495/00

Abstract:
Present invention relates to an improved process for the preparation of Zopiclone and its enantiomerically enriched isomer (Eszopiclone). 6-(5-Chloropyridin-2-yl)-5-hydroxy-7-oxo-5,6-dihydropyrrolo[3,4-b]pyrazine is reacted with 1-chloro-carbonyl-4-methylpiperazine in the presence of alkali earth metal carbonates, hydroxides or oxides in a solvent medium to give Zopiclone. It is reacted with optically active acid in a mixture of water and water miscible organic solvent followed by work up to give Eszopiclone. The present invention also relates to process for the conversion of (R) or (S) Zopiclone to 6-(5-chloropyrid-2-yl)-5-hydroxy-7-oxo-5,6-dihydro-pyrrolo-[3,4-b]-pyrazine of the intermediate which can be converted to racemic Zopiclone.
Public/Granted literature
- US20100056785A1 Preparation Of Zopiclone And Its Enantiomerically Enriched Isomer Public/Granted day:2010-03-04
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