STUDIES ON PHENOTHIAZINES .16. SYNTHESIS AND SPECTRAL STUDIES OF SUBSTITUTED 1,2-DICHLOROPHENOTHIAZINES

Synthesis of the title compounds by the Smiles rearrangement has been reported. 1,2-Dichloro-7-substituted phenothiazines have been prepared by the Smiles rearrangement of 3,4-dichloro-2-formamido-2'-nitro-4'-substituted-diphenyl sulphides. The latter were obtained by the formylation of the diphenyl sulphides obtained by the condensation of 2-amino-3,4-dichlorobenzenethiol with o-halogenonitrobenzenes. 9-Nitro-phenothiazines have been prepared by the reaction of 2-amino-3,4-dichlorobenzenethiol with substituted o-halonitrobenzenes containing a nitro group at both ortho positions to the halo atom in which Smiles rearrangement occurs in situ. The ir, nmr and mass spectral studies are also included.