(3-Chlorophenyl)methanesulfonyl chloride was prepared as follows: thiourea (0.387 g, 5 mmol) and m-chlorobenzyl chloride (5 mmol) were dissolved in 5 mL of ethanol, and the reaction was carried out at reflux for 30 min, then the solvent was removed under reduced pressure to obtain a white solid. This white solid was slowly added dropwise to a mixed system of NaClO2 (1.61 g, 15 mmol, 85% purity), concentrated HCl (3 mL) and MeCN (10 mL). The temperature in the reaction system was controlled between 10 and 20oC with a water bath during the addition process. After the addition was completed, the reaction was continued with stirring for 30 min, the acetonitrile was removed under low temperature and under reduced pressure, 25 mL of water was added, and the solids in the system were filtered and dried to obtain the product colorless crystals of (3-chlorophenyl)methanesulfonyl chloride with a melting point of 76-78oC, 1.035 g, and a yield of 92%.
