Angular heterocycles. Utilization of arylaminonaphthoquinones in the synthesis of benzophenothiazines

Substituted 6-ethoxyanilino-5H-benzoa]phenothiazin-5-ones (3a-f) were synthesized by the cyclocondensation of 2-chloro-3-ethoxyanilino-1,4-naphthoquinones with zinc mercaptides of 2-aminothiophenol in pyridine. The nmr, ir and mass spectral data are presented and discussed.