Abstract N-Phenylmaltimide reacted with chlorosulfonic acid to give an excellent yield of the sulfonyl chloride (1), which with dimethylamine or aniline (2 equivs.) afforded the corresponding sulfonamides (2, 3). However, use of more dimethylamine (4 equivs.) caused opening of the imido ring and addition to the double bond to yield the dimethylamide (12). Similar reaction with diethylamine in methanol resulted in nucleophilic ring-opening by the ...