The reaction of urea derivatives that contain the phenothiazine unit with trifluoromethanesulfonic anhydride in the presence of electron-rich aromatic compounds leads to the formation of arenecarboxamides. The reaction has been successfully demonstrated for several inter- and intramolecular systems.

Urea derivatives that contain a phenothiazine unit react with electron rich arenes in the presence of triflic anhydride to give the corresponding arenecarboxamides.