Method for preparing 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone

Abstract

The invention discloses a method for preparing 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone, which comprises the following steps: reacting 3,3-dimethyl-2-butanone and p-chlorobenzaldehyde under reflux for 5-10 hours by using methanol as a solvent and sodium methoxide as an alkalizer, recycling part of methanol, cooling to 10-20 DEG C, filtering to obtain the 4,4-dimethyl-1-(4-chlorphenyl)-3-pentanone, and drying, wherein the mol ratio of p-chlorobenzaldehyde:3,3-dimethyl-2-butanone:sodium methoxide is 1:(1.0-1.3):(1.2-1.5). Methanol is substituted for potassium hydroxide, so that water generated in reaction is decomposed by sodium methoxide, thereby effectively enhancing the reaction speed and reaction yield; and since the reaction system does not contain water, the solvent can be recycled by simple distillation, thereby greatly lowering the facility request and reducing the raw material unit consumption. The synthesis yield of the method is higher than 97%, the product content is higher than 96%, and the recovery rate of the solvent methanol is up to 85%; and thus, the invention can easily implement industrial production, has good practicality, and can generate high economic benefit and social benefit.

Description

technical field [0001] The invention belongs to the technical field of organic compound synthesis, and specifically relates to a method for preparing 4,4-dimethyl-1-(4-chlorophenyl)-3-pentanone. Background technique [0002] 4,4-Dimethyl-1-(4-chlorophenyl)-3-pentanone is an important intermediate of the triazole pesticide tebuconazole. At present, there are many domestic manufacturers, all of which use p-chlorobenzaldehyde Reaction with 3,3-dimethyl-2-butanone in the presence of potassium hydroxide and methanol as a solvent. The disadvantages of this process are that the synthesis yield is about 85%, the product quality is poor, the content is about 90%, and a large amount of water is produced. Methanol can be reused only after rectification, which requires high equipment and high loss. Contents of the invention [0003] Purpose of the invention: In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing 4,4-dim...

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Problems solved by technology

[0002] 4,4-Dimethyl-1-(4-chlorophenyl)-3-pentanone is an important intermediate of the triazole pesticide tebuconazole. At present, there are many domestic manufacturers, all of which use p-chlorobenzaldehyde Reaction with 3,3-dimethyl-2-butanone in the presence of potassium hydroxide and methanol as a solvent. The disadvantages of this process are that the synthesis yield is about 85%, the product quality is poor, the content is about 90%, and a large amount of water is produced. Methanol, methanol can be reused only after rectification, high equipment requirements and large loss

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