Method for synthesizing p-fluorobenzoyl chloride

Abstract

The invention discloses a method for synthesizing p-fluorobenzoyl chloride. The method is characterized by comprising the following steps: adding bis(trichlormethyl) carbonate into a reaction kettle filled with parafluorobenzoic acid and 1,2-dichloroethane, reacting in the presence of a catalyst, filtering, and performing reduced pressure distillation, thereby obtaining p-fluorobenzoyl chloride. The selected acylating chlorination reagents are green and environment-friendly, the raw materials are low in price and readily available, the synthetic process is mild in conditions, the purity of the finally obtained product can be 99.9 percent, and the product has wide application prospects and industrial values.

Description

technical field [0001] The invention relates to the field of preparation of fluorine-containing intermediates, in particular to a synthetic method of p-fluorobenzoyl chloride. Background technique [0002] p-Fluorobenzoyl chloride is an important fluorine-containing intermediate and an important intermediate for the synthesis of fluorine-containing drugs flunarizine, lomerizine, and almitrigine. Its special application is that it is a special high-performance engineering plastic An important intermediate of the monomer 4,4'-difluorobenzophenone of polyetheretherketone (PEEK). [0003] At present, there are many publicly reported routes for the synthesis of p-fluorobenzoyl chloride, mainly as follows: U.S. Patent US 2006 / 12879A1 reports that it is prepared by reacting p-fluorobenzoic acid with thionyl chloride. The shortcoming of this route is the preparation of by-products A large amount of acid gas is produced, which is more corrosive to equipment; U.S. Patent US6187952B1 ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many publicly reported routes for the synthesis of p-fluorobenzoyl chloride, mainly as follows: U.S. Patent US 2006 / 12879A1 reports that it is prepared by reacting p-fluorobenzoic acid with thionyl chloride. The shortcoming of this route is the preparation of by-products A large amount of acid gas is produced, which is more corrosive to equipment; U.S. Patent US6187952B1 reports that p-fluorobenzaldehyde is used as a raw material and prepared by chlorination. The shortcoming of this reaction is that the price of the raw material p-fluorobenzaldehyde used is relatively high Expensive, cause the cost of this route to be too high; Literature "organic fluorine industry" 2011,4,46-47 has reported that take p-fluorotoluene as raw material, pass into chlorine gas under ultraviolet lamp, obtain p-fluorotrichloromethylbenzene, then The product is obtained through hydrolysis and distillation. The shortcoming of this route is that the experiment uses light reaction, which is not conducive to large-scale industrial production, and the reaction is not easy to control, and it is easy to obtain p-fluorobenzoic acid by-product; Document Journal of Labeled Compounds and Radiopharmaceuticals, 2013,56,309 -618 reported that p-fluorobenzoic acid was used as the starting material, after oxalyl chloride (COCl) 2 Chlorination, the disadvantage of this reaction is that the cost of chlorination reagents is relatively high, which is not conducive to industrial production