Add 150g (1mol) of trifluoromethanesulfonic acid to the reactor equipped with thermometer, distillation device and mechanical stirrer, slowly add 435mL (6mol) of thionyl chloride under ice bath, and then add the catalyst N,N-dimethyl Formamide 7.36 (0.1 mol), slowly raise the temperature to room temperature, stir for half an hour, continue to heat up to 40°C, continue to stir, react for 12 hours, and then drop to room temperature after the reaction is complete.Subsequently, vacuum distillation was carried out at 110° C. and -0.1 to -0.08 MPa, and at the same time, the temperature was slowly raised to 50° C. to obtain 147 g of trifluoromethanesulfonyl chloride, with a yield of 87.5%.
