Method for preparing ethyl bromodifluoroacetate

Abstract

The invention provides a method for preparing ethyl bromodifluoroacetate and relates to a preparation method of a chemical reagent. The method takes trichloro ethylene as a raw material, and comprisesthe following steps: under the action of ultraviolet light of a catalytic medium, an oxidation reaction happens between trichloro ethylene and oxygen in a reactor to synthesize dichloracetyl chloride; an amination reaction happens between dichloracetyl chloride and diethylamine under the action of a catalyst to synthesize dichloroacetyl diethylamine; a fluorination reaction happens between dichloroacetyl diethylamine and anhydrous potassium fluoride under the action of a solvent and a phase transfer catalyst to synthesize difluoroacetyl diethylacetamide; difluoroacetyl diethylacetamide is esterified to synthesize ethyl difluoroacetate; and by taking cupric bromide as a brominating agent, ethyl difluoroacetate is bromized to prepare the end product (ethyl bromodifluoroacetate). The methodhas the characteristics that the equipment investment is low, reaction conditions are mild, the method is safely implemented at normal pressure, and after-treatment is simple.

Description

technical field [0001] The invention relates to a preparation method of chemical reagents, in particular to a preparation method of ethyl difluorobromoacetate. Background technique [0002] The synthesis of ethyl difluorobromoacetate is a relatively classic intermediate synthesis reaction, and the research on its synthesis process is also very rich. The most commonly used is to prepare alcohols with bromodifluoroacetyl halides (acyl fluorides, acid chlorides or acid bromides). These bromodifluoroacetyl halides are generally prepared by 1,1-difluorotetrahalogenated ethane such as CF 2 BrCFClBr, CF 2 BrClBr 2 、CF 2 BrCBr 3 、CF 2 BrCF 2 Br is produced by oxidation with sulfuric acid in the presence of metal salt catalysts, especially in the presence of mercury salt catalysts. [0003] Although there are many synthetic methods for ethyl difluorobromoacetate, some raw materials for the synthesis of ethyl difluorobromoacetate are either difficult to obtain in industry, or a...

AI Technical Summary

Problems solved by technology

[0003] Although there are many synthetic methods for ethyl difluorobromoacetate, some raw materials for the synthesis of ethyl difluorobromoacetate are either difficult to obtain in industry, or are very dangerous to handle, requiring very special instruments and devices, so increased production costs