Racemization method of eszopiclone

A technology for zopiclone and racemization, which is applied in the field of racemization of zopiclone, can solve the problems of high requirements for reaction conditions and complicated process, and achieve the effects of wide solvent range, simple operation, good yield and purity

Active Publication Date: 2012-09-26
四川弘远药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method greatly improves the utilization rate of zopiclone, but what is obtained after the racemization is not zopiclone, but a degradation product of zopiclon

Method used

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  • Racemization method of eszopiclone

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0027] Preparation of reference substance solution: adopt the self-control method, take 1ml to 100ml of the test solution, and dilute to the mark with acetonitrile.

[0028] Preparation of the test solution: take an appropriate amount of sample, add acetonitrile to make each 1ml containing 1mg of eszopiclone.

[0029] Product optical isomer ratio determination of the present invention:

[0030] Chromatographic conditions and system suitability experiment: mobile phase is 0.02M sodium acetate: acetonitrile = 93:7, detection wavelength is 225nm, flow rate is 0.7ml / min, column temperature is 25°C, column is CHIRAL-AGP (100*4.0mm) . The system applicability is that the theoretical plate is not less than 800 based on the calculation of eszopiclone, and the separation degree of eszopiclone and eszopiclone is greater than 1.5.

[0031] Preparation of reference substance solution: standardize by yourself, take an appropriate amount of reference substance, add mobile phase to dissolv...

Embodiment 1

[0035] Eszopiclone (1.0g, R / S=95.25 / 4.75, measured by HPLC) and TMG (100mg) were added in 16ml butanone, and the mixture was refluxed under stirring for 8 hours, then slowly cooled to room temperature, and then used Refrigerate overnight (0 to -20°C), filter with suction, wash with water, drain, and dry with hot air circulation at 80°C for 8 hours to obtain 0.6 g of racemic zopiclone (yield 60%, R / S=50.1 / 49.9, chemical Purity 99.4% by HPLC).

Embodiment 2

[0037] Add eszopiclone (1.0 g, R / S=95.25 / 4.75 (as determined by HPLC)) and TMG (50 mg) into 9 ml of acetonitrile, and the mixture was stirred and refluxed for 3 hours, then slowly cooled to room temperature, and then cooled with a refrigerator Freeze overnight (0 to -20°C), filter with suction, wash with water, drain, and dry with hot air circulation at 80°C for 8 hours to obtain 0.84g racemic zopiclone (yield 84%, R / S=50.0 / 50.0, chemical purity 99.9% by HPLC).

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Abstract

The invention relates to a racemization method of eszopiclone. According to the invention, tetramethylguanidine which is cheap and easily available is used as a racemization agent. The method provided by the invention is simple to operate, is safe and stable, has advantages of high yield and good product quality, and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of pharmaceutical synthesis, in particular to a racemization method of eszopiclone. Background technique [0002] Zopiclone is a pyrrolidone compound with hypnotic, sedative, muscle relaxant, anxiolytic and anticonvulsant effects. It was developed and marketed as a racemate in 1987 by the French company Rhone-poulenc Rorer. Zopiclone is a non-benzodiazepine compound that selectively acts on GABA (γ-aminobutyric acid)-benzodiazepine receptors to produce a central inhibitory effect and exert a sedative and hypnotic effect. It is a fast-acting hypnotic. [0003] Eszopiclone is the right-handed isomer of zopiclone, the chemical name is (+)-6-(5-chloropyridin-2-yl)-7(S)-(4-methylpiperazine-1- (yl)carbonyloxy)-6,7-dihydro-5-hydro-pyrrole[3,4-b]pyrazin-5-one. It was developed and produced by Sepracor Pharmaceuticals in Massachusetts, USA. It was approved for clinical use by the FDA on December 16, 2004, and it we...

Claims

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Application Information

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IPC IPC(8): C07D487/04
Inventor 杜小春严峻
Owner 四川弘远药业有限公司
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