Refining method of high-purity epalrestat

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

Active Publication Date: 2015-11-18
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

Method used

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  • 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 into a 5000ml three-necked bottle, and stir under reflux in the dark at 110°C to dissolve. Stand at ~40°C for 3-5h, suction filter at 30-35°C, wash the filter cake once with a small amount of 80% aqueous methanol solution, dry at 60°C, and weigh to obtain 416.5g of epalrestat with a purity of 99.744%. Yield 86.3%.

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

[0029] batch number

Embodiment 2

[0031] Add 500g of epalrestat and 845ml of tetrahydrofuran into a 5000ml three-necked bottle, and stir under reflux at 110°C in the dark to dissolve, then continue to add 2600ml of 80% methanol aqueous solution to it after dissolving, stir for 5 minutes, and then stand at 35-40°C Suction filtration at 30-35°C for 3-5 hours, the filter cake was washed once with a small amount of 80% aqueous methanol solution, dried at 60°C, 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 into a 5000ml three-necked bottle, and stir under reflux at 110°C in the dark to dissolve, then continue to add 3300ml of ethanol to it after dissolving, stir for 5min, and then stand at 35-40°C Leave it for 3-5 hours, suction filter 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 in particular provides a method for refining high-purity epalrestat. Background technique [0002] Epalrestat, chemical name 5-[(1Z,2E)-2-methyl-3-phenyl-2-propenyl]-4-oxo-2-thio-3-thiazolidine Acetic acid, molecular formula: C 15 h 13 NO 3 S 2 , molecular weight: 319.40, chemical structural formula: [0003] [0004] Epalrestat was developed by Ono Pharmaceutical Co., Ltd., Japan, and was first launched in Japan in 1992 under the trade name of Kinedak, which was 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 has a tendency to increase, but there is no specific drug for treatment. Diabetic neuropathy is a common and early complication of diabetes, which has a great impact on the quality of life of patients. It is generally be...

Claims

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Application Information

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IPC IPC(8): C07D277/36
CPCC07D277/36
Inventor 李栋李兆林
Owner KANGYA OF NINGXIA PHARMA
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