Process for producing p-toluenesulfonyl chloride

The present invention is a new method of producing p-toluenesulfonyl chloride with methylbenzene and chlorosulfonic acid as material and the said method is that after the reaction of methylbenzene and chlorosulfonic acid, the product produces crystal mixture at the stirring speed of 2-50 rpm in crystallizer with the crystalization temp. being minus 10 to plus 30 deg.C and crystallization time being 1-8 hr, and after direct filtration and water washing, p-toluenesulfonyl chloride is obtained. The said method has short technological period, low power consumption, high product quality and low material consumption, and the waste sulfuric acid produced in technological process has a concentration over 90% and is easy to re-use.