Refining method of crude epalrestat product

A technology of epalrestat and refining method, which is applied in the field of refining epalrestat crude product and medicine purification, can solve the problems such as inability to obtain high-purity epalrestat, and achieve simple operation, high yield and good reaction conditions mild effect

Active Publication Date: 2015-06-17
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 refining method of epalrestat crude product of the present invention, the detailed steps of this refining method are as follows:

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

[0033] b. Secondary refining:

[0034] Add 8.0 g of epalrestat after initial p...

Embodiment 2

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

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

[0038] b. Secondary refining:

[0039] Add 8.1 g of epalrestat after initial purification in step a to 32.4 ml of solvent tetrahydrofuran, heat t...

Embodiment 3

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

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

[0043] b. Secondary refining:

[0044]Add 8.22 g of epalrestat after init...

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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 Patents(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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