Vacuum system method for preparing acyl chloride by benzal dichloride hydrolysis

Abstract

The invention discloses a vacuum system method for preparing acyl chloride by benzal dichloride hydrolysis. According to the vacuum system method for preparing acyl chloride by benzal dichloride hydrolysis raw material benzal chloride used in production is adopted to replace traditional water to serve as a vacuum circulating medium, non-condensable materials brought out in the acyl chloride decompression rectification process are absorbed into a vacuum circulating liquid tank, circulating liquid is cooled through a heat exchanger, and heat generated in circulating medium spraying process is removed; periodically transferring of a benzylidene dichloride absorption liquid is carried out, returned benzylidene dichloride absorption liquid to an acyl chloride synthesis kettle is taken as a material for preparing acyl chloride, and supplement of fresh benzylidene dichloride into the vacuum circulating liquid tank is carried out. According to the method, a vacuum system is improved, acyl chloride is prevented from reacting when meeting water to generate gas, the stable operation of the vacuum system is ensured, no organic wastewater is generated, materials in the vacuum tail gas are recycled, and the raw material consumption of acyl chloride production is reduced.

Description

technical field [0001] The patent of the present invention relates to a method of a vacuum system in the process of preparing acid chlorides by acidolysis of benzylidene dichloride. Background technique [0002] Acyl chloride is an important carboxylic acid derivative with active chemical properties, which can undergo various reactions such as hydrolysis, alcoholysis, ammonia (amine) solution, reaction with organometallic reagents, reduction reaction, α-hydrohalogenation, etc. , pharmaceutical synthesis, resource environment and other aspects have important applications, [0003] Acyl chlorides are generally prepared by reacting organic acids with phosphorus trichloride, phosphorus pentachloride or thionyl chloride. The main production methods are phosphorus trichloride method, phosphorus pentachloride method, thionyl chloride method, phosgene method, four Carbon chloride method. [0004] Thomas J, McCann in the patent (patent US3691217:Process for the perparation of acyl ...

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