Methanesulfonyl chloride (100 g, 1.0 eq.) was added slowly and dropwise to a stirred ethanol solution of monomethylamine (8 M in EtOH, 525 mL, 4.8 eq.) at 0 °C. After the dropwise addition, the reaction mixture was warmed to room temperature and stirred continuously for 16 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was diluted with dichloromethane (200 mL) and the isolated solid was filtered. The filtrate was concentrated to afford the target product, N-methylsulfonylmethylamine, as an orange oil (82 g, yield not indicated). The product was characterized by 1H NMR (CDCl3, 400 MHz): δ 4.819 (broad single peak, 1H), 2.929 (single peak, 3H), 2.789 (single peak, 3H).
