A kind of refining method of high-purity epalrestat

A technology of epalrestat and refining method, applied in the direction of organic chemistry, etc., can solve the problems of low purity and yield of the final product, difficult operation, etc., and achieve the effect of convenient operation, single solvent, and small amount of solvent

Active Publication Date: 2016-07-06
KANGYA OF NINGXIA PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] In summary, the refining methods of epalrestat in the prior art all have the following deficiencies: two recrystallizations are required, and thermal filtration is required, the operation is difficult, and the purity and yield of the final product obtained are low

Method used

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  • A kind of refining method of high-purity epalrestat
  • A kind of refining method of high-purity epalrestat
  • A kind of refining method of high-purity epalrestat

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add 500g of epalrestat and 750ml of 1,4-dioxane to a 5000ml three-necked bottle, stir at 110°C in the dark and reflux to dissolve, continue to add 3000ml of 80% methanol aqueous solution after the dissolution, and stir for 5min at 35 Let stand at ~40 °C for 3 ~ 5 h, and filter at 30 ~ 35 °C with suction. The filter cake is washed once with a small amount of 80% methanol aqueous solution, dried at 60 °C, and weighed to obtain 416.5 g of epalrestat with a purity of 99.744%. Yield 86.3%.

[0028] Three consecutive batches of small test experimental data:

[0029] lot number

Embodiment 2

[0031] Add 500g of epalrestat and 845ml of tetrahydrofuran to a 5000ml three-necked flask, stir at 110°C in the dark and reflux to dissolve, continue to add 2600ml of 80% methanol aqueous solution to it after dissolving, stir for 5min and let stand at 35~40°C 3~5h, suction filtration at 30~35℃, the filter cake is washed once with a small amount of 80% methanol aqueous solution, dried at 60℃, and weighed to obtain 406.7g of epalrestat with a purity of 99.517% and a yield of 81.3%.

Embodiment 3

[0033] Add 500g of epalrestat and 550ml of dimethylformamide to a 5000ml three-necked bottle, stir at 110°C in the dark and reflux to dissolve, continue to add 3300ml of ethanol after dissolving, stir for 5min, and let it stand at 35~40°C. Set it for 3-5 hours, suction filtration at 30-35 °C, wash the filter cake once with a small amount of ethanol, dry at 60 °C, and weigh to obtain 392.0 g of epalrestat with a purity of 99.601% and a yield of 78.4%.

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Abstract

The invention provides a refining method of high-purity epalrestat. The refining method comprises the following steps of: adding the epalrestat into a good solvent, keeping out of light at the temperature of 110 DEG C, stirring, refluxing, and dissolving; after dissolving, adding a bad solvent into the mixture, maintaining the temperature, standing for crystallization, carrying out suction filtration, cleaning a filter cake for one time by using the bad solvent, drying at the temperature of 60 DEG C and obtaining a finished epalrestat product. The structure of the epalrestat is as shown in the specification. Compared with the prior art, the refining method provided by the invention has the advantages that the used refining solvent is low in cost and easy to obtain, the reaction condition is mild, the production cost is low, the pollution is less, the operation is simple, heat filtration is not needed, only once recrystallization is needed, the purity and the yield of the obtained finished epalrestat product are high, the quality of the product is improved, and the suitability for massive industrial production is achieved.

Description

technical field [0001] The invention belongs to the technical field of medicine, and particularly provides a purification method of high-purity epalrestat. Background technique [0002] Epalrestat, chemical name 5-[(1Z,2E)-2-methyl-3-phenyl-2-propenylene]-4-oxo-2-thio-3-thiazolidine Acetic acid, molecular formula: C 15 H 13 NO 3 S 2 , molecular weight: 319.40, chemical structure: [0003] [0004] Epalrestat was developed by Japan's Ono Pharmaceutical Co., Ltd. and was first marketed in Japan in 1992 under the trade name Kinedak, approved for the treatment of diabetic neuropathy. [0005] Diabetes is a disease that seriously endangers human health. With the gradual improvement of people's living standards, the incidence of diabetes is increasing, but there is no effective drug for treatment. Diabetic neuropathy is one of the common and early complications of diabetes, which has a great impact on the quality of life of patients. It is generally believed that diabeti...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D277/36
CPCC07D277/36
Inventor 李栋李兆林
Owner KANGYA OF NINGXIA PHARMA
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