Synthesis of 3-bromo-1-methylphenothiazines by smiles rearrangement

3-Bromo-1-methyl phenothiazines have been prepared by the Smiles rearrangem ent of 5-bromo-2-formamido-3-methyl-2'-nitro-4'-diphenyl sulfides. The form yl derivatives were prepared by the formylation of the resultant diphenyl s ulfides obtained by the condensation of 2-amino-5-bromo-3-methylbenzenethio l with o-halonitrobenzene in ethanolic acetate solution. However, halonitro benzenes containing a nitro group at both ortho positions to the reactive h alogen atom on condensation with 2-amino-5-bromo-3-methylbenzenethiol direc tly yielded 7-bromo-9-methyl nitro phenothiazine as Smiles rearrangement oc curs in situ.