In a 2000 mL four-necked flask equipped with a stirrer, a reflux condenser and a thermometer, 1650 g of 1,2-dichloroethane and 550 g (4.80 mol) of methanesulfonyl chloride were added, and ice brine was cooled to 10 C, and a dry anhydrous monomethylamine gas was slowly passed through at the beginning, and with the passage of the monomethylamine, the temperature was slowly increased, and the control of the normal passage temperature was 20-30 C. Along with the passage of the monomethylamine, a The white solid slowly increased (monomethylamine hydrochloride), to the passage of about 5h, a total of 302g (9.72mol) of monomethylamine. Stop the ventilation, continue to hold the reaction for 30min, sampling GC detection, the remaining 0.15% of methanesulfonyl chloride, the end of the reaction. The flask was connected to a water vacuum pump, pumped at 20-30 for 2h, then cooled the suspension to 10 , and held for 30min, filtered the solids, a transparent solution. Decompression distillation of ethylene dichloride, a total of 1450g of ethylene dichloride was recovered, and finally distilled under vacuum at 112~116 /-0.098MPa until the content of ethylene dichloride was <0.4% as detected by GC, to obtain the finished product of N-methylmethanesulfonamide.
