Synthesis of 7-ethoxy- and 7-fluoro-phenothiazines

Synthesis of 7-ethoxy- and 7-fluoro-phenothiazines is reported by Smiles rearrangement of 5-ethoxy- and 5-fluoro-2-formamido-2′-nitrodiphenylsulfides. The later were obtained by the formylation of 2-amino-5-ethoxy/5-fluoro-2′-nitrodiphenylsulfides which were prepared by the condensation of 2-amino-5-ethoxy/5-fluoro-benzenethiols with o-halonitrobenzenes.