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Synthetic reaction of calcium dobesilate hydrate

A calcium dobesilate hydrate and sulfonation reaction technology, which is applied in the preparation of sulfonate, organic chemistry, etc., can solve the problems of long synthesis route, complex process, high equipment requirements, etc., achieve mild reaction conditions and simplify process steps , The effect of improving crystal purity

Active Publication Date: 2012-07-18
KANGYA OF NINGXIA PHARMA
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  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

[0006] But above each test method all exists in varying degrees the shortcomings such as high pollution, low yield, complicated process, as described in (1), because the method synthesis route is long, the requirement to equipment is high, the three wastes are difficult to handle, and the impact on the environment Large pollution; (2) due to the use of nitrogen for protection, complex process, low yield, and difficult recovery of organic solvents; (3) due to the use of toxic solvents, do not use environmental protection; (4) using Low temperature operation, large energy consumption, and use of flammable and explosive solvents, does not utilize industrialized large-scale production; most steps in (5) adopt low temperature operation, energy consumption is large, the use of organic solvents increases the manufacturing cost of medicines, and does not use the environment (6) The purity of the product is low, it is difficult to control the impurity amount of hydroquinone, resulting in certain side effects of the product

Method used

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  • Synthetic reaction of calcium dobesilate hydrate
  • Synthetic reaction of calcium dobesilate hydrate
  • Synthetic reaction of calcium dobesilate hydrate

Examples

Experimental program
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Effect test

example 1

[0025] Put 1.2kg of concentrated sulfuric acid with a concentration of 90% in the reaction kettle, add 1.25kg of hydroquinone under stirring, then add 0.4kg of concentrated sulfuric acid, heat up to 80°C while stirring, keep stirring for 2 hours, add 2.5kg of purified water, stirred, slowly added calcium carbonate, kept at 60°C until the pH value of the liquid reached 4.5, which was the end point of the reaction, and stopped adding calcium carbonate to the reaction kettle; centrifugally filtered, the filter cake was washed with purified water, separated Calcium sulfate, take the filtrate and put it in a concentration kettle, heat and concentrate until the specific gravity of the medicinal solution is 1.3g / ml, then stop the concentration, take the concentrated solution, cool and crystallize at room temperature, filter, and obtain about 2.4kg of crude product.

[0026] Put 2.4kg of crude product in a concentration kettle, add 0.8kg of purified water, stir, raise the temperature t...

example 2

[0031] Put 1.25kg of concentrated sulfuric acid with a concentration of 85% in the reaction kettle, add 1.25kg of hydroquinone under stirring, heat up to 70°C while stirring, keep warm and stir for 1 hour, add 3.0kg of purified water, stir, slowly Slowly add calcium carbonate, keep at 60°C until the pH value of the liquid reaches 4.5, which is the end point of the reaction, stop adding calcium carbonate to the reaction kettle; centrifugally filter, wash the filter cake with purified water, separate calcium sulfate, take the filtrate and put it in the concentration kettle Concentrate by heating until the specific gravity of the medicinal solution is 1.3g / ml, stop the concentration, take the concentrated solution, cool and crystallize at 6°C, and filter to obtain about 2.2kg of crude product.

[0032] Put 2.2kg of crude product in a concentration kettle, add 0.8kg of purified water, stir, raise the temperature to 60°C, keep the temperature, concentrate under reduced pressure unti...

example 3

[0037] Put 1.7kg of concentrated sulfuric acid with a concentration of 90% in the reaction kettle, add 1.25kg of hydroquinone under stirring, raise the temperature to 85°C while stirring, keep stirring for 1 hour, lower the reaction temperature to 25°C, and add purified water 2.5kg, stir, slowly add calcium carbonate, and slowly heat up to 60 ° C, keep warm, add calcium carbonate until the pH value of the liquid reaches 3.5, which is the end of the reaction, stop adding calcium carbonate to the reactor; centrifugal filtration, filtration Wash the cake with purified water, separate the calcium sulfate, take the filtrate and put it in the concentration kettle, heat and concentrate until the specific gravity of the liquid is 1.3g / ml, stop the concentration, take the concentrated solution, cool and crystallize at room temperature, and filter to obtain the crude product About 2.5kg.

[0038] Put 2.5kg of crude product in a concentration kettle, add 0.8kg of purified water, stir, ra...

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Abstract

The invention relates to a synthesizing process of calcium dobesilate hydrate in pharmaceutical industry. Hydroquinone and concentrated sulfuric acid are directly sulfonated and then the sulfonated product in water solution state and calcium carbonate are neutralized to prepare the calcium dobesilate hydrate. In the synthesizing process, the operation is simplified, the industrialization cost is saved, the reaction conditions are mild, the product purity is high, the reaction end point is controllable, and the process is suitable for industrial mass production.

Description

technical field [0001] The invention relates to a synthesis process of calcium dobesilate hydrate in the pharmaceutical industry. Background technique [0002] The chemical name of calcium dobesilate is 2,5-dihydroxybenzenesulfonate, and its structural formula is: [0003] [0004] First listed in 1971 by the French company Carroin, it is a widely used microvascular circulation improving agent in the world, used to prevent and treat various diseases caused by porch circulation disorders. [0005] The synthetic technique method of this compound that domestic and international research report roughly contains following several: (1) take hydroquinone as starting material, add through potassium dichromate and potassium hydrosulfate, replace with perchloric acid (2) under the protection of inert gas nitrogen, hydroquinone is sulfonated with concentrated sulfuric acid, and prepared by azeotropic dehydration of organic solvent ethyl acetate-ethanol; (3) utilizing hydroquinone t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C309/42C07C303/32
Inventor 杨亚军马国龙龙红娟
Owner KANGYA OF NINGXIA PHARMA
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