Synthesis of 10‐aminophenothiazines and derivatives

Abstract

Abstract In this paper it is shown that 2‐nitro‐2′‐(β‐acetyl) hydrazinodiphenyl sulfides cyclize, via a Smiles rearrangement, to 10‐acetylaminophenothiazines, which are inert to alkalis and suffer a strong decomposition by acids. 10‐Aminophenothiazine has been obtained by ring closure of 2‐bromo‐2′‐hydrazinodiphenyl sulfide via an assumed benzyne intermediate.