A method for synthesizing eszopiclone

A synthetic method, hemiacetal technology, applied in organic chemistry, etc., can solve the problems of expensive esterase, long reaction time, and lack of industrial application value, and achieve the effect of easy-to-obtain catalyst, low production cost, and cheap catalyst

Inactive Publication Date: 2019-11-22
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The esterase used in this method is relatively expensive, and the reaction time is very long, so it does not have industrial application value at present

Method used

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  • A method for synthesizing eszopiclone
  • A method for synthesizing eszopiclone
  • A method for synthesizing eszopiclone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021]

[0022] Add racemic hemiacetal 5.24g (20mmol) in the reaction flask, (R)-6-tert-butyl-2,3,5,6-tetrahydroimidazol[2,1-and]thiazole 0.37g ( 2mmol), Et 3 N 2.7 mL and 100 mL dry CH 2 Cl 2 . A solution of 2.5 mL of phenyl chloroformate dissolved in 100 mL of dichloromethane was slowly added dropwise at room temperature. After the addition was complete for about 1 hour, the reaction was stirred overnight at room temperature. Add 10%Na 2 CO 3 The pH of the solution was adjusted to 8-9, the organic layer was separated, and the aqueous layer was extracted with dichloromethane (100 mL×2). The combined organic layers were dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography [V (ethyl acetate): V (petroleum ether) = 2: 3] to obtain (S)-hemicondensate Aldehyde phenyl carbonate 3.2g, yield 41.8%, ee value measured by Daicel Chiralcel AS-H chiral chromatographic column is 85%. ...

Embodiment 2

[0024] Using the same procedure as in Example 1, replace (R)-6- tert-butyl-2,3,5,6-tetrahydroimidazo[2,1-]thiazole was used as a catalyst to obtain 3.1 g of (S)-hemiacetal phenyl carbonate with a yield of 40.0% and an ee value of 82% .

Embodiment 3

[0026] Using the same procedure as in Example 1, replace (R)-6- tert-butyl-2,3,5,6-tetrahydroimidazo[2,1-]thiazole was used as a catalyst to obtain 2.7 g of (S)-hemiacetal phenyl carbonate with a yield of 35.0% and an ee value of 90% .

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Abstract

The invention provides a method for synthesizing eszopiclone. According to the method, chiral imidazo thiazole is taken as a catalyst to catalyze a racemic hemiacetal intermediate and chloro-formic ester to produce kinetic resolution reaction, and (S)-hemiacetal carbonic ester with good yield and enantioselectivity is obtained. The (S)-hemiacetal carbonic ester is reacted with N-methyl piperazine, so that eszopiclone can be obtained. The method has the advantages that the chiral imidazo thiazole which is low in cost and easy to obtain is used as the catalyst, operation procedures are simple, the production cost is low, and the method has very high application value for the industrial preparation of eszopiclone.

Description

technical field [0001] The invention relates to a new method for synthesizing anti-insomnia drug eszopiclone, which belongs to the field of drug synthesis. Background technique [0002] Zopiclone is an anti-insomnia drug, which produces central inhibitory activity by selectively acting on GABA receptors. It has a rapid onset of action and few side effects, and is widely used in clinical practice. Eszopiclone is the dextrorotatory form of zopiclone, developed by Sepracor Pharmaceuticals of the United States and first listed in the United States in 2005. The hypnotic activity of eszopiclone is about twice that of zopiclone, and the side effects are smaller, so it has significant advantages in clinical application. [0003] The industrial preparation of eszopiclone is currently through the chiral resolution of racemic zopiclone. In patents WO2008126105A2, CN 103193779, US 20050043311, US 20070054914, it is reported that D-dibenzoyl tartaric acid or D-di-p-toluyl tartaric acid...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D487/04
CPCC07D487/04
Inventor 鄢明刘玉张学景
Owner SUN YAT SEN UNIV
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