Refining method of crude epalrestat product

A technology of epalrestat and a refining method, which is applied to the purification of medicine and the refining field of crude epalrestat, can solve the problems of inability to obtain high-purity epalrestat and the like, and achieves easy operation, mild reaction conditions, and high yield. high effect

Active Publication Date: 2013-03-20
KAIFENG MINGREN PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Through literature research, epasstat with a total impurity of about 0.3% is generally achieved in the prior art, but in experiments, it is found that a single solvent cannot obtain high-purity epasstat with a total impurity less than 0.1%

Method used

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  • Refining method of crude epalrestat product
  • Refining method of crude epalrestat product
  • Refining method of crude epalrestat product

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] The method for refining crude epalrestat of the present invention, the detailed steps of the refining method are as follows:

[0032] a. One-time refining: first dissolve 10g crude epalrestat in 30ml solvent tetrahydrofuran, heat to 55~65℃ to completely dissolve the crude epalrestat, stop heating after complete dissolution, and then slowly add 70ml solvent isopropyl ether. After adding, a small amount of red solid precipitated. Continue heating to 55~65℃ to completely dissolve the red solid and stop heating. Cool naturally to crystallize for 5h. After crystallizing, filter, obtain wet product of epalrestat after filtration. The obtained wet product of epalrestat was dried, the drying temperature was 100°C, and the drying time was 1h. After drying, 8.0g of the first refined epalrestat was obtained, and the yield was 80.0%;

[0033] b. Secondary refining:

[0034] Add 8.0g of epalrestat after first refining in step a to 24ml of solvent tetrahydrofuran, heat to 55~65℃ to complet...

Embodiment 2

[0036] The method for refining crude epalrestat of the present invention, the detailed steps of the refining method are as follows:

[0037] a. One-time refining: first dissolve 10g crude epalrestat in 40ml solvent tetrahydrofuran, heat to 50~55℃ to completely dissolve the crude epalrestat, stop heating after complete dissolution, then slowly add 80ml solvent isopropyl ether, After adding, a small amount of red solid precipitated out. Continue heating to 50~55℃ to completely dissolve the red solid and stop heating. Cool naturally for 5.5h to crystallize, filter after crystallizing, and obtain the wet product of epalrestat after filtering. The resulting wet product of epalrestat was dried at a drying temperature of 90°C and a drying time of 2h. After drying, 8.1 g of epalrestat was obtained after the initial purification, with a yield of 81.0%;

[0038] b. Secondary refining:

[0039] Add 8.1g of epalrestat after the first refining in step a to 32.4ml of solvent tetrahydrofuran, heat...

Embodiment 3

[0041] The method for refining crude epalrestat of the present invention, the detailed steps of the refining method are as follows:

[0042] a. One-time refining: first dissolve 10g crude epalrestat in 20ml solvent tetrahydrofuran, heat to 65~70℃ to completely dissolve the crude epalrestat, stop heating after complete dissolution, then slowly add 60ml solvent isopropyl ether, After adding, a small amount of red solid precipitated out. Continue heating to 65~70℃ to completely dissolve the red solid and stop heating. Cool naturally to crystallize for 6h, filter after crystallizing, and obtain a wet product of epalrestat after filtration. The obtained wet product of epalrestat was dried, the drying temperature was 120°C, and the drying time was 1h. After drying, 8.22g of the first refined epalrestat was obtained, and the yield was 82.2%;

[0043] b. Secondary refining:

[0044] Add 8.22g of epalrestat after first refining in step a to 16.5ml of solvent tetrahydrofuran, heat it to 65~70...

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Abstract

The invention discloses a refining method of a crude epalrestat product, which comprises the following steps of: firstly, dissolving the crude epalrestat product into a tetrahydrofuran solvent, heating to completely dissolve the crude epalrestat product, and stopping heating after the crude epalrestat product is completely dissolved; then adding isopropyl ether so that a small amount of red solids are separated out, further heating to completely dissolve the red solids, then stopping heating, naturally cooling, crystallizing and filtering, and then drying to obtain initially refined epalrestat; and then adding the tetrahydrofuran solvent, heating till the initially refined epalrestat is completely dissolved, stopping heating, then slowly adding petroleum ether so that a small amount of red solids are separated out, continuously heating till the red solids are completely dissolved, then stopping heating, naturally cooling, crystallizing and filtering, and then drying to obtain a refined epalrestat product. The refining method disclosed by the invention can be used for obtaining the high-purity epalrestat and has the advantages that the solvent raw material is available, reaction condition is mild, operation is simple and yield is high, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a method for purifying medicine, which belongs to the field of medicinal chemistry, in particular to a method for refining crude epalrestat. Background technique [0002] Epalrestat was first listed in Japan in 1992. It is a reversible non-competitive aldose reductase inhibitor of carboxylic acids and has obvious curative effect on diabetic complications. The chronic complications of eyes, kidneys, nerves, blood vessels, heart, and organs caused by diabetes are the direct causes of blindness, lower limb gangrene, uremia, stroke or myocardial infarction, and even life-threatening. [0003] It is now known that certain metabolic pathways and signal transduction pathways play a very important role in the development of diabetic complications. For example, under normal circumstances, only about 5% of the glucose in the cell enters the polyol channel, but in the state of diabetes, the polyol channel is activated, and about 30% of t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D277/36
Inventor 张宏波张宝国李沁沁王斐毛影杨晓霞
Owner KAIFENG MINGREN PHARMA
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