Method for preparing medicinal high-purity calcium dobesilate

A calcium dobesilate, high-purity technology, applied in the preparation of organic compounds, chemical instruments and methods, organic chemistry, etc., can solve the problem of difficult removal of hydroquinone impurities

Inactive Publication Date: 2011-10-19
BEIJING ZHENDONG GUANGMING PHARMA RES INST +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Hydroquinone and its oxidation product p-benzoquinone and other impurities exist in the crude product of calcium 2,5-dihydroxybenzenesulfonate synthesized by this process.

Method used

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  • Method for preparing medicinal high-purity calcium dobesilate
  • Method for preparing medicinal high-purity calcium dobesilate
  • Method for preparing medicinal high-purity calcium dobesilate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Add 35.2g (0.320mol) of hydroquinone to a 100ml reaction bottle, slowly add 38ml of concentrated H 2 SO 4 (including H 2 SO 4 0.563mol), controlled the temperature at 80°C for 1hr, then added 300ml of 75% ethanol aqueous solution and stirred to dissolve. Slowly add 70.4g (0.704mol) of powdered CaCO in batches 3 Neutralize excess H 2 SO 4 , and adjust the pH to 2.5-5.0. After suction filtration, the filtrate was extracted twice with 280 mL of a mixed solvent of acetone and ethyl acetate at a ratio of 5:4. The aqueous layer was separated, concentrated under reduced pressure, and the concentrated solution was placed for crystallization. After suction filtration, the filter cake was washed twice with the above aqueous ethanol solution to obtain 48.2 g of crude calcium dobesilate.

[0045] Dissolve the above crude product in 50 mL of water, add 50 mL of 75% ethanol aqueous solution, stir evenly, concentrate under reduced pressure, and stand for crystallization. Suc...

Embodiment 2

[0047] Add 5.00Kg (45.4mol) of hydroquinone to the 50L reactor, slowly add 4L concentrated H 2 SO 4 (including H 2SO 4 75.1 mol), the temperature was controlled at 80° C. for 1 hr, and then 40 L of 75% ethanol aqueous solution was added and stirred to dissolve. Slowly add 10.0Kg (100mol) powdered CaCO in batches 3 Neutralize excess H 2 SO 4 , and adjust the pH to 2.5-5.0. After suction filtration, the filtrate was extracted twice with 40 L of mixed solvent of acetone and ethyl acetate at a ratio of 1:4. The aqueous layer was separated, concentrated under reduced pressure, and the concentrated solution was placed for crystallization. After suction filtration, the filter cake was washed twice with the above ethanol aqueous solution to obtain 7.63 kg of crude calcium dobesilate.

[0048] The above crude product was dissolved in 8 L of water, and 8 L of the above ethanol aqueous solution was added to stir evenly, concentrated under reduced pressure, and left for crystalli...

Embodiment 3

[0050] With embodiment 2 technique, drop into 5.00Kg (45.4mol) Hydroquinone, finally obtain the pure product 6.17Kg of pharmaceutically acceptable calcium dobesilate. The overall yield based on hydroquinone was 62.3%. HPLC purity 99.8%, hydroquinone impurity content 0.007%, total impurity content 0.136%. The test results are attached image 3 .

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PUM

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Abstract

The invention relates to a method for preparing medicinal high-purity calcium dobesilate. The method comprises the following steps of: 1, treating a coarse product of calcium dobesilate by using an organic solvent; and 2, re-crystallizing by using an aqueous solution of ethanol, wherein the organic solvent is acetone, ethyl acetate or a mixed solvent of acetone and ethyl acetate, and a volume ratio (V/V) of the acetone to the ethyl acetate is 1:5-5:1.

Description

Technical field: [0001] The invention relates to a preparation method of a pharmaceutical compound, in particular to a method for purifying calcium dobesilate, a medicine for treating diabetic eye disease. Background technique: [0002] At present, the incidence of diabetes is on the rise, and the incidence of diabetes-related complications is also increasing. Diabetic nephropathy is the most common complication of diabetes. According to reports, in the United States, diabetic nephropathy accounts for the first end-stage renal failure, about 35% to 38%. At present, diabetic nephropathy is also an important cause of chronic renal failure in my country. Diabetic nephropathy and diabetic retinopathy both belong to diabetic microangiopathy, and both have the direct toxic effect of hyperglycemia and enhanced oxidative stress level, etc., and have a common basis for pathogenesis. [0003] Calcium dobesilate (Calcium Dobesilate, 2,5-dihydroxybenzenesulfonate calcium monohydrate)...

Claims

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Application Information

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IPC IPC(8): C07C309/42C07C303/44
Inventor 郭德嵩李豪王成霞仰振球
Owner BEIJING ZHENDONG GUANGMING PHARMA RES INST
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