Novel production process for dichloroacetonitrile

Abstract

The invention relates to a novel production process for dichloroacetonitrile, specifically to a novel synthetic process for a key intermediate dichloroacetonitrile of a fine chemical engineering product, i.e., florfenicol. Dichloroacetonitrile is a key intermediate of florfenicol, and florfenicol is a novel special wide-spectrum veterinary chloramphenicol antibiotic successively developed in later 80s and is used as a feed additive for a pig for prevention and treatment of swine bacterial diseases. When same dosages of florfenicol and spiramycin are used for treatment of respiratory diseases, the cure rate (91%) of florfenicol is substantially higher than the cure rate (41%) of spiramycin; and when 50 ppm of florfenicol is mixed with a feed for treatment of man-induced swine actinobacillus pleuropneumonia, a cure rate reaches 100%. The process provided by the invention mainly overcomes the problems of severe reaction conditions, high danger, high reaction temperature, slow reaction rate, low yield, poor controllability and the like of conventional processes. According to the process, dichloroacetamide and dichlorine pentoxide are subjected to a reflux reaction in a liquid environment with dichloroacetonitrile so as to obtain a crude product, and the crude product undergoes rectification so as to obtain a qualified product. The process has the advantages of mild reaction conditions, no pollution, high yield, high content, high added value of a byproduct and high economic benefits and environmental protection benefits.

Description

technical field [0001] The invention relates to a new production process of dichloroacetonitrile, specifically designed to a new synthesis process of dichloroacetonitrile, an important intermediate of the fine chemical product Florfenicol. Background technique [0002] Dichloroacetonitrile is an important intermediate of Florfenicol. Florfenicol is a new veterinary-specific broad-spectrum antibacterial drug of chloramphenicol successfully developed in the late 1980s. It was first launched in Japan in 1990 and was launched in 1993. In 1995, Norway approved the drug to treat furunculosis in salmon, and in 1995, France, the United Kingdom, Austria, Mexico and Spain approved it to treat bacterial diseases of the respiratory system of cattle. It is used as a feed additive for pigs to prevent and treat bacterial diseases in pigs. Our country has passed the approval of this drug at present. Florfenicol was originally mainly used in aquaculture, and it was used to treat pseudokaryo...

AI Technical Summary

Problems solved by technology

Yet there are many problems in the dichloroacetonitrile production technology that adopts at present, (1) two kinds of raw materials used in the reaction process are all solid, and the contact of solid material is very insufficient, so reaction rate is low, and the resistance of solid material is big, to reaction Kettle, stirring and other equipment requirements are high

(2) In the process of reflux reaction, it is necessary to provide high temperature and vacuum distillation. The risk factor is relatively large, and there are great safety hazards in the operation process.

(3) Under the influence of insufficient reaction between solid and solid, resulting in low product yield and low product content

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