Preparation method of 3',5'-dichloro-2,2,2-trifluoroacetophenone

Abstract

The invention relates to the technical field of chemical pharmacy, particularly to a preparation method of 3',5'-dichloro-2,2,2-trifluoroacetophenone. According to the invention, 3',5'-dichloro-2,2,2-trifluoroacetophenone is prepared from 3'-chloro-2,2,2-trifluoroacetophenone as a raw material through four steps of nitrification, reduction, chlorination and deamination, and the method has the advantages of low raw material cost, mild reaction conditions, simple reaction process, facilitation of the reduction of the production cost, and improvement of the economic effect.

Description

technical field [0001] The present application relates to the technical field of chemical industry and pharmacy, in particular to a preparation method of 3′,5′-dichloro-2,2,2-trifluoroacetophenone. Background technique [0002] 3′,5′-Dichloro-2,2,2-trifluoroacetophenone is an important intermediate used in the synthesis of pesticides and veterinary drugs. [0003] In the prior art, the synthesis methods of 3′,5′-dichloro-2,2,2-trifluoroacetophenone mainly include the following types: [0004] 1. The PCT patent with the application number WO2018009751 discloses a preparation method using 3,5-dichlorobromobenzene and methyl trifluoroacetate as starting materials, using tetrahydrofuran as a solvent, by adding 3,5-dichlorobromobenzene React with isopropylmagnesium chloride-lithium chloride to prepare Grignard reagent and then react with methyl trifluoroacetate. In the above-mentioned prior art, isopropylmagnesium chloride and tetrahydrofuran are relatively expensive and explosi...

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Problems solved by technology

[0004] 1. The PCT patent with the application number WO2018009751 discloses a preparation method using 3,5-dichlorobromobenzene and methyl trifluoroacetate as starting materials, using tetrahydrofuran as a solvent, by adding 3,5-dichlorobromobenzene React with isopropylmagnesium chloride-lithium chloride to prepare Grignard reagent and then react with methyl trifluoroacetate. In the above-mentioned prior art, isopropylmagnesium chloride and tetrahydrofuran are relatively expensive and explosive, and the production cost in industrial production higher, less economical

[0005] 2. The Chinese invention patent whose publication number is CN107353189A discloses a kind of 3,5-dichlorobromobenzene as a raw material, which is reacted with a trifluoroacetyl compound under the action of butyllithium to obtain 3,5-dichlorobromobenzene and The preparation method of methyl trifluoroacetate, similarly, the price of tert-butyllithium in this method is expensive, and the risk is great, and the whole reaction needs to be carried out under the condition of -78 ℃, and the industrial production cost is higher, and the economic effect is relatively poor

[0006] In the above two existing technologies, the cost of raw materials is relatively high, and the reaction conditions are relatively harsh. Some flammable, explosive and expensive raw materials are used in the reaction process, which increases the cost of industrial production and has an economic effect in large-scale production. poor

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