144025-94-5

Basic information

• Product Name: (R)-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate D-(+)-O,O'-dibenzoyltartaric acid salt
• Synonyms: (R)-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate D-(+)-O,O'-dibenzoyltartaric acid salt
• CAS NO: 144025-94-5
• Molecular Weight: 747.118
• Mol File: 144025-94-5.mol
• Article Data: 6

Chemical Properties

• CAS DataBase Reference: (R)-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate D-(+)-O,O'-dibenzoyltartaric acid salt(CAS DataBase Reference)
• NIST Chemistry Reference: (R)-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate D-(+)-O,O'-dibenzoyltartaric acid salt(144025-94-5)
• EPA Substance Registry System: (R)-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate D-(+)-O,O'-dibenzoyltartaric acid salt(144025-94-5)

Safety Data

• Hazardous Substances Data: 144025-94-5(Hazardous Substances Data)

Upstream product

• 1020156-02-8 D(+)-O,O-dibenzoyl tartarate of zopiclone 
• 43200-83-5 3-((5-chloropyridin-2-yl)carbamoyl)pyrazine-2-carboxylic acid 
• 43200-82-4 6-(5-chloro-2-pyridyl)-5,7-dioxo-6,7-dihydro-5H-pyrrolo(3,4-b)pyrazine 
• 55112-42-0 4-methylpiperazine-1-carbonyl chloride monohydrochloride 
• 43200-81-3 6-(5-chloropyridin-2-yl)-7-hydroxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-one 
• 4744-50-7 2,3-pyrazinedicarboxylic anhydride 
• 1072-98-6 5-chloro-2-pyridylamine 
• 17026-42-5 O,O'-dibenzoyl-D-tartaric acid 
• 43200-80-2 zopiclon 

Downstream Products

• 138680-08-7 (-)-Zopiclone 
• 43200-81-3 6-(5-chloropyridin-2-yl)-7-hydroxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-one 

Relevant articles and documents

A method for preparing eszopiclone

The invention relates to an eszopiclone preparation method comprising main steps that: zopiclone is subjected to a reaction with D-dibenzoyltartaric acid or a hydrate thereof, such that dextral zopiclone-D-dibenzoyltartrate is produced; and the salt is dissociated, such that eszopiclone is obtained. According to the method, D-dibenzoyltartaric acid with a substance amount of a quarter to a half of that of zopiclone is adopted. The reaction conditions are mild, operation is convenient, product yield is high, and product purity is high. The method is suitable for large-scale industrialized productions.

PROCESS FOR PREPARATION OF DEXTROROTATORY ISOMER OF 6-(5-CHLORO-PYRID-2-YI)-5-[(4-METHYL -1-PIPERAZINYL) CARBONYLOXY]-7-OXO-6,7-DIHYDRO-5H-PYRROLO [3,4-B] PYRAZINE (ESZOPICLONE)

Disclosed herein is the process for preparation of 6-(5-chloro-pyrid-2-yl)-5-[(4-methyl-1-piperazinyl) carbonyloxy]-7-oxo-6,7-dihydro-5H-pyrrolo [3,4-b] pyrazine (Zopiclone), its resolution to get the dextrorotatory isomer of formula (I) substantially free of R (-) enantiomer and recovery of key raw material i.e. 6-(5-chloro pyrid-2-yl)-5-hydroxy-7-oxo-5,6-dihydropyrrolo [3,4-b] pyrazine from the R-isomer of Zopiclone followed by conversion of the recovered compound to get pure Eszopiclone (I) in high yield and high purity.

IMPROVED PROCESS FOR THE PREPARATION OF ZOPICLONE AND IT'S ENANTIOMERICALLY ENRICHED ISOMER

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.