of trifluoromethanesulfonyl azide in solvents composed of 1:1 mixtures of benzene and substituted benzenes gives trifluoromethanesulfonanilide and substituted trifluoromethanesulfonanilides. The isomer ratios, the total rate ratios, and the partial rate factors for the sulfonamidation have been determined. By the intramolecular and intermolecular selectivities, the reaction mechanism involving trifluoromethanesulfonyl