Synthesis of 4H‐pyrazolo‐ and 4H‐pyrrolophenothiazin‐4‐one derivatives

Abstract

5‐Methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones were condensed with 2‐aminobenzenethiol or 6‐substituted‐3‐aminopyridine‐2(1H)thiones 4 to produce a new type of 5‐methyl‐2‐phenyl‐4H‐pyrazolophenothiazin‐4‐ones or 8‐substituted‐7‐aza‐5‐methyl‐2‐phenyl‐4H‐pyrazolophenothiazin‐4‐one derivatives. From 6‐bromo‐2,5‐dimethyl‐1,3‐diphenyl‐2H‐isoindole‐4,7‐dione and 4 8‐substituted‐7‐aza‐2,5‐dimethyl‐1,3‐diphenyl‐4H‐pyrrolophenothiazin‐4‐one derivatives were also prepared.