A mixture of 23.5 g (0.25 mol) of freshly distilled dimethyl disulfide and 51 g (0.5 mol) of acetic anhydride is chlorinated at -10 to 0℃. During the course of the reaction the color changes from yellow to red and then disappears, at which point the addition of chlorine is suspended, leading to 126 g of reaction mixture. This is distilled in a 45 cm Vigreux column at 2 kPa with cooling. Acetyl chloride distills at 0℃, and at 47–48℃ the almost colorless methanesulfinyl chloride is obtained in 83–86% yield.
