M-hydroxy acetophenone preparation method

A technology of m-hydroxyacetophenone and hydroxyacetophenone, which is applied in the field of preparation of m-hydroxyacetophenone, can solve the problems of large waste water discharge, high environmental protection cost, and high cost, and achieve small waste water discharge, avoid pollution, low cost effect
CN108530277AInactive Publication Date: 2018-09-14JIANGXI YONGTONG TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
JIANGXI YONGTONG TECH
Publication Date
2018-09-14
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses an m-hydroxy acetophenone preparation method which includes the steps: performing chlorination, dissolving m-hydroxybenzoic acid in methylbenzene, adding 4-dimethylamino pyridine serving as a catalyst, adding acyl thionyl chloride for chlorination to obtain m-hydroxybenzoic acid acyl chloride, and then removing the acyl thionyl chloride by concentration and evaporation to obtain m-hydroxybenzoic acid acyl chloride-methylbenzene solution; dissolving dimethyl malonate sodium salt in methylbenzene to obtain dimethyl malonate sodium salt-methylbenzene solution, dripping them-hydroxybenzoic acid acyl chloride-methylbenzene solution obtained in the step (1) into the dimethyl malonate sodium salt-methylbenzene solution, and then performing reflux reaction for 3-5 hours atthe reaction temperature of 50-80 DEG C to obtain a product A; adding the obtained product A into hydrochloric acid solution, and performing hydrolysis reaction to obtain m-hydroxy acetophenone. Thepreparation method is simple in process, small in wastewater discharge amount, low in cost and high in yield and final product purity.
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Description

Technical field

[0001] The invention relates to a preparation method of m-hydroxyacetophenone, belonging to the technical field of organic synthesis. Background technique

[0002] M-hydroxyacetophenone is a needle-like crystal. The melting point is 95-97°C, the boiling point is 296°C, 153°C (0.67kPa), the relative density is 1.099 (109°C), and the refractive index is 1.5348. Soluble in ethanol; ether; chloroform and benzene, slightly soluble in water, insoluble in petroleum ether. Used in organic synthesis, it is an intermediate of the drug phenylephrine.

[0003] The conventional production method is derived from the reaction between m-aminoacetophenone and sodium nitrite. Add water and sulfuric acid into the reaction pot, add m-aminoacetophenone under stirring, then add dropwise sodium nitrite aqueous solution under cooling, keep the temperature at 8-10℃, slowly increase the temperature to above 90℃ after the addition, continue stirring the reaction 1h. The solid is precipit...

Claims

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