Method for preparing difluoroacetyl fluoride

Abstract

The invention discloses a method for preparing difluoroacetyl fluoride from 1-C1-C8-alkoxy-1,1,2,2-tetrafluoroethane as a raw material by gas-phase catalytic cracking reaction in the presence of an aluminum fluoride catalyst. According to the disclosed preparation method, the reaction route is concise and efficient, fewer by-products are generated, catalytic activity is high, catalyst stability ishigh, and industrial production is facilitated.

Description

technical field [0001] The invention relates to a preparation method of halogenated acid halides, in particular to a preparation method of difluoroacetyl fluoride. Background technique [0002] Alkyl difluoroacetate is a kind of widely used chemical and pharmaceutical intermediates, and its common preparation method is to react difluoroacetyl fluoride with alcohol. For the preparation method of difluoroacetyl fluoride, in the prior art, alkoxytetrafluoroethane is usually obtained by reacting tetrafluoroethylene with alcohol, and then the alkoxytetrafluoroethane is cracked to generate difluoroacetyl fluoride. In the process of cracking alkoxytetrafluoroethane to generate difluoroacetyl fluoride, it is very important to find a suitable catalyst. For catalysts, the prior art has made the following efforts: [0003] Chinese patent CN102218304A discloses a method of using 1,1,2,2-tetrafluoroethyl alkyl ether as a raw material for catalytic cracking to obtain the target product ...

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Problems solved by technology

Although when using this γ-alumina catalyst after HF fluorination treatment, the conversion rate reaches more than 99%, and the selectivity is greater than 95%, but the fluorination treatment time of this catalyst is too long and the hydrogen fluoride flow rate constantly changes in the fluorination treatment process. The whole process is not easy to control

[0006] In summary, although the prior art has made some improvements to the catalysts used to prepare difluoroacetyl fluoride from the cracking of alkoxytetrafluoroethane, there are generally problems such as catalyst activity or service life, catalyst preparation or activation process complexity, etc.

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