REACTION OF NORMAL AND PSEUDO 2-FORMYLBENZENESULFONYL CHLORIDES WITH AMINES - EXPERIMENTAL AND THEORETICAL-STUDIES ON THE STRUCTURE OF 2-FORMYL BENZENESULFONAMIDES IN SOLID, SOLUTION AND GAS PHASES

The reaction of 2-formylbenzenesulfonyl chloride 1 and its pseudo isom er 2 with primary amines give either the corresponding sulfonamido Sch iff bases or the corresponding 2-formylbenzenesulfonamide depending on the concentration of the amine used. The derivatives exist as an equi librium mixture of the corresponding sulfonamide and 2-alkyl-3-hydroxy (or 3-aminoalkyl)-benzisothiazole-1,1-dioxide. Spectroscopic studies s uggest that 2-formylbenzenesulfonamides exist as benzisothiazole-1,1-d ioxides in the solid state, as a mixture of 2-formylbenzenesulfonamide and the corresponding benzisothiazole-1,1-dioxide in solution and as 2-formyl-benzenesulfonamides in the gas phase.