Conformation of 2-thiophenesulphonanilides from dipole moment studies

Abstract

The electric dipole moments of a number of 2-thiophenesulphonanilides have been measured in benzene solution at 25 °C. The data obtained have been analyzed by the vectorial additive method of calculation. Results of the calculations have shown that the SO2—NH group prefers the gauche-syn conformation in which the N—H bond lies on the plane bisecting the OSO angle. Conformations about the Ph—N bond in the 2′- and 3′-substituted derivatives have also been determined and are discussed.