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Process for synthesizing hydrate of calcium phenolsulfonate

A calcium dobesilate hydrate and synthesis process technology, which is applied in the field of synthesis process of calcium dobesilate hydrate, can solve the problems of difficult recovery, complex process, high equipment requirements, etc., and achieve the advantages of recycling and simplifying the process The effect of mild operation and process conditions

Inactive Publication Date: 2005-08-10
XIAN LIJUN PHARMA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

The synthetic process method of this compound domestic and foreign research report probably has the following several kinds: (1) take hydroquinone as starting material, through the addition of potassium dichromate and potassium hydrosulfate, and then replace trichloride with calcium perchlorate One-step reaction synthesis, the method has a long route, high requirements on equipment, and the three wastes are also difficult to handle, causing great environmental pollution
(2) Under the protection of inert gas nitrogen, hydroquinone is sulfonated with concentrated sulfuric acid, and the organic solvent ethyl acetate-ethanol is prepared by azeotropic dehydration. The organic solvent of this route is difficult to recover, and the process is complicated and the yield is relatively low. Low
(3) Utilize hydroquinone to react with concentrated sulfuric acid dropwise in halogenated hydrocarbons, and then neutralize it with calcium carbonate to prepare. This route uses carbon tetrachloride or 1,2-dichloroethane as a toxic solvent, in which 1 , 2-dichloroethane was listed as a carcinogenic hydrocarbon by the American Association of Environmental Chemistry in 1984, which is not conducive to the physical and mental health of workers and environmental protection
(4) Utilize hydroquinone to be sulfonated with concentrated sulfuric acid in an ether solvent (such as diethyl ether) at low temperature, and neutralized with calcium carbonate to prepare it. This route operates at low temperature, consumes a lot of energy, and uses flammable and explosive solvent ethers , not conducive to industrial production and environmental protection

Method used

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  • Process for synthesizing hydrate of calcium phenolsulfonate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0009] Add 44 grams of hydroquinone and 53.5 milliliters of concentrated sulfuric acid (90% by weight) into the reaction flask, stir while raising the temperature to 75°C, and after insulated and stirring for 3 hours, cool down to 25°C and add 60% (V / V) 200 milliliters of ethanol water, heat up to 50°C, stir and dissolve completely, add about 60 grams of powdered calcium carbonate, adjust the pH value to about 3.0, stop the reaction, filter to remove calcium sulfate, concentrate under reduced pressure P=0.085MPa, T< After fine crystals appeared at 60°C, the concentration was stopped, and the crystallization was placed at 8°C for 6 hours, then filtered and dried to obtain 75 g of crude product.

[0010] Add 75 grams of crude product and 20 ml of water into the reaction flask, stir, and heat up to 65°C. After dissolving, remove the insoluble matter by hot filtration, and concentrate the filtrate under reduced pressure, P=0.08~0.95MPa, T 99.5%.

[0011] The finished product has ...

Embodiment 2

[0023] Add 880 grams of hydroquinone and 800 milliliters of concentrated sulfuric acid (93% by weight) into the reaction flask, heat up to 95° C. under stirring, and obtain a gray-white viscous substance after 2 hours of heat preservation reaction, cool down to 40° C., add 55% ( V / V) 4000 milliliters of ethanol water, after heating up to 55°C to dissolve, add about 800 grams of powdered calcium carbonate, adjust the pH to about 5, stop the reaction, remove calcium sulfate by the same process, concentrate under reduced pressure, crystallize, dry and other processes Process, get about 1500 grams of crude product.

[0024] Add the above crude product into the reaction flask together with 700 milliliters of water, stir and heat up to 50° C., after dissolving, remove the insoluble matter by hot filtration, and post-process by the same process to obtain 1430 grams of finished product, the yield (mole) is about 82%, and the content (no water)>99.5%.

[0025] The finished product has...

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Abstract

A process for synthesizing the hydrate of calcium phenol sulfonate includes sulfonating reaction of hydroquinone with concentrated sulfuric acid, dissolving in aqueous solution of alcohol, adding calcium carbonate to regulate pH to 2.5-5, filtering, vacuum concentrating, cooling, crystallizing to obtain coarse product, dissolving in water, thermal filtering, vacuum concentrating, cooling, crystallizing, suction filtering, washing and drying. Its advantrages are simplified process, low cost, high yield, and less pollution.

Description

technical field [0001] The invention relates to a synthesis process of calcium dobesilate hydrate in the pharmaceutical industry. Background technique [0002] Calcium dobesilate (Calcium dobesilate) chemical name is 2,5-dihydroxybenzenesulfonate calcium, which was first listed by the French company Carroin in 1971. It is a microvascular circulation improving agent widely used in the world, and is used for the prevention and treatment of microvascular circulation. Various diseases caused by circulatory disorders. The synthetic process method of this compound domestic and foreign research report probably has the following several kinds: (1) take hydroquinone as starting material, through the addition of potassium dichromate and potassium hydrosulfate, and then replace trichloride with calcium perchlorate One-step reaction synthesis, this method has a long route, high requirements on equipment, and the three wastes are also difficult to handle, causing great environmental pol...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C303/06C07C303/32C07C309/42
Inventor 王文潮王海燕曲秦解萍
Owner XIAN LIJUN PHARMA CO LTD
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