New derivatives of the leprostatic drug dapsone are prepared by way of imino-1, 2, 3- dithiazoles obtained by condensation of aromatic primary bisamines, including dapsone, with 4, 5-dichloro-1, 2, 3-dithiazolium chloride (Appel salt). Reactions, including microwave irradiation, initiated by nucleophilic attack at different sites of the dithiazole ring transform the bisiminodithiazoles into the symmetrical, and some unsymmetrical, title compounds.
