Clean preparation method for 2,4-dichloro-alpha-chloromethyl benzyl alcohol

Abstract

The invention discloses a clean preparation method for 2,4-dichloro-alpha-chloromethyl benzyl alcohol and belongs to the field of catalytic synthesis process of 2,4-dichloro-alpha-chloromethyl benzyl alcohol. 2,2',4'-trichloroacetophenone is taken as an initial raw material, aluminium isopropoxide serves as a catalyst, isopropyl alcohol serves as not only a solvent but also a reactant, and reduction reaction, reduced pressure distillation, acidation, water washing and curing are conducted to obtain the 2,4-dichloro-alpha-chloromethyl benzyl alcohol. An isopropyl alcohol and acetone mixed solution obtained through reduced pressure distillation is rectified, 80-84 DEG C fraction is collected for recycling, and the yield is basically kept unchanged. Acidized acid water is neutralized by ammonia water, then filtered to obtain aluminium hydroxide, and finally roasted to acquire aluminium oxide after being dried. The method is mild in reaction conditions, short in reaction time and convenient in after-treatment, and avoids environmental pollution. The conversion rate and the product yield of 2,2',4'-trichloroacetophenone are more than 99%, and the manufacturing cost is low. The method is an efficient and environmental-friendly method for synthesizing 2,4-dichloro-alpha-chloromethyl benzyl alcohol and facilitates large-scale industrial production.

Description

technical field [0001] The invention relates to a method for cleanly preparing 2,4-dichloro-α-chloromethyl benzyl alcohol, which belongs to the technical field of catalytic synthesis of 2,4-dichloro-α-chloromethyl benzyl alcohol. Background technique [0002] 2,4-Dichloro-α-chloromethyl benzyl alcohol is an important intermediate for the synthesis of spectrum antifungal drugs such as miconazole nitrate, econazole nitrate, nitrofenticonazole, and ethanazole, usually in the form of 2, 2',4'-Trichloroacetophenone is used as raw material and obtained through reduction reaction. The traditional acidifying agent is mostly dilute sulfuric acid or dilute hydrochloric acid, but due to the dehydration, esterification and oxidation of concentrated sulfuric acid, a series of side reactions are caused, which makes the product dark in color, the post-treatment process is complicated, the waste liquid pollutes the environment, and corrodes the equipment. serious. Dilute hydrochloric acid...

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Problems solved by technology

[0003] At present, there have been reports in China on the preparation of 2,4-dichloro-α-chloromethyl benzyl alcohol by lithium aluminum hydride, sodium borohydride, aluminum isopropoxide, etc., but there are various degrees of pollution, corrosion of equipment, and inconvenient operation. Disadvantages such as high cost, large investment cost, and difficulty in industrialization implementation

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