144025-93-4

Basic information

• Product Name: eszopiclone dibenzoyl-D-tartrate
• Synonyms: eszopiclone dibenzoyl-D-tartrate
• CAS NO: 144025-93-4
• Molecular Weight: 747.118
• Mol File: 144025-93-4.mol
• Article Data: 7

Chemical Properties

• CAS DataBase Reference: eszopiclone dibenzoyl-D-tartrate(CAS DataBase Reference)
• NIST Chemistry Reference: eszopiclone dibenzoyl-D-tartrate(144025-93-4)
• EPA Substance Registry System: eszopiclone dibenzoyl-D-tartrate(144025-93-4)

Safety Data

• Hazardous Substances Data: 144025-93-4(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 
• 43200-81-3 6-(5-chloropyridin-2-yl)-7-hydroxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-one 
• 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 
• 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

• 138729-47-2 eszopiclone 

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.

A NOVEL PROCESS FOR THE PREPARATION OF ESZOPICLONE

The present invention is related to a novel process for the preparation of eszopiclone (II), that comprises the following steps: (a) preparation of zopiclone (I) by reaction of 6-(5-chloropyridin-2-yl)-5-hydroxy-7-oxo- 5,6-dihydropyrrolo[3,4-b]pyrazine-5-one (5-OH-Py) (III) with chloro-carbonyl-4- methyl-piperazine (CMP) free base (IV) or its acid addition salt in the presence of diazabicylo [5.4.0]undec-7-ene (DBU) or a mixture of DBU and other bases; (b) resolution of racemic zopiclone with dibenzoyl-D-tartaric acid in suitable solvent wherein dibenzoyl-D-tartaric acid addition salt of eszopiclone is separated by the addition of a nitrile solvent; (c) optional purification of dibenzoyl-D-tartaric acid addition salt of eszopiclone by dissolution in solvent selected from alcohols, ketones or mixture thereof followed by the precipitation by adding a nitrile solvent; (d) conversion of the dibenzoyl-D-tartaric acid addition salt of eszopiclone to obtain the eszopiclone free base (II) by treating with an alkaline solution; (e) purification of eszopiclone by dissolving in nitrile solvent followed by addition of ketonic solvent. The eszopiclone (II) obtained by the process of the present invention has chiral purity greater than 99.9% and less amounts of organic volatile impurities. The present invention further provides novel crystalline form B of eszopiclone- Dibenzoyl-D-tartarate salt (V) and its preparation.

Process for Preparation of Dextrorotatory Isomer of 6-(5- chloro-pyrid-2-yl)-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.