(reagent used in a wide array of ene-reactions and cycloadditions) Physical Data: mp 73 °C; bp 110–120 °C at 0.004 mbar. Solubility: soluble in benzene, toluene, diethyl ether, chloroform, and several other aprotic solvents. Form Supplied in: pale yellow needles; not commercially available. Preparative Methods: prepared from benzenesulfonamide by heating in thionyl chloride with catalytic amounts of TMSCl, or from N,N-dichlorobenzene sulfonamide, or the Na salt of N-chlorobenzenesulfonamide,1 or by treating benzenesulfonamide with N-(chlorosulfinyl)imidazole.2 Purification: vacuum distillation at 0.004 mbar, then recrystallization from toluene. Handling, Storage, and Precautions: store under nitrogen atmosphere and refrigerate. Do not heat above 170 °C during distillation. Incompatible with protic solvents. Decomposes on prolonged exposure to air and humidity