A kind of synthesis technique of ethyl difluoroacetate

Abstract

The invention relates to a production technology of ethyl difluoroacetate, specifically to a synthesis technology of ethyl difluoroacetate. The technology comprises the following steps: (1) 2,2,2-trifluoroethyl alcohol and chloroethane are subjected to an etherification reaction under the action of a catalyst so as to obtain trifluoro ethyl ether; (2) trifluoro ethyl ether obtained in the step (1) undergoes a defluorination reaction under the alkaline condition to generate difluoro ethyl vinyl ether; (3) difluoro ethyl vinyl ether obtained in the step (2) and ethanol are subjected to an addition reaction in the presence of a catalyst p-toluenesulfonic acid so as to obtain acetal; and (4) acetal obtained in the step (3) is oxidized under the combined action of hydrogen peroxide and vanadic anhydride so as to obtain ethyl difluoroacetate. The invention has the following beneficial effects: the synthesis method is simple, has characteristics of less pollution, high product purity and low production cost, etc., and provides a new approach to large-scale production of ethyl difluoroacetate.

Description

technical field [0001] The invention relates to a production process of ethyl difluoroacetate, in particular to a synthesis process of ethyl difluoroacetate. Background technique [0002] Ethyl difluoroacetate is an important organic intermediate, mainly used in medicine, pesticide, organic synthesis and other fields. There are many downstream pharmaceutical products of ethyl difluoroacetate, most of which are in the process of in-depth research on pharmacology, safety, and clinical studies. The large-scale production of ethyl difluoroacetate has broad market prospects. [0003] JP6228043 patent discloses a production method for synthesizing difluoroacetic acid from dichloroacetic acid derivatives through fluorination of fluoride salts. For example: the reaction of dichloroacetyl chloride and diethylamine in toluene solvent at 10°C gives 89% of N,N-diethyldichloroacetamide, and N,N-diethyldichloroacetamide reacts at 150°C with Potassium fluoride in diethylene glycol is hea...

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Problems solved by technology

There are problems such as the use of explosive raw materials and highly toxic by-products in the production process of the process route using tetrafluoroethylene as raw material; the route using R132a as raw material adopts photocatalytic oxidation method, which has the disadvantage that it is not easy to scale up in production; The process of preparing difluoroacetic acid from 1,2-dichloro-3,3-difluoropropene-1 has problems such as difficult access to raw materials and high pollution, which is not conducive to large-scale production; The production of ethyl difluoroacetate by amination, fluorination, and esterification has many side reactions, and there are many "three wastes" and serious pollution problems, which affect the large-scale production of ethyl difluoroacetate. This problem needs to be solved urgently

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