Patent ID: 8691979
Filing Date: 2014-04-08
Classification: A61P,C07C,C07D

Abstract:
1. A method for the preparation of a diaminophenothiazinium compound, the method comprising the steps of (i) Thiosulfonic Acid Formation (TSAF); and (ii) Oxidative Coupling (OC); wherein the diaminophenothiazinium compound has the following formula: and: wherein step (i) Thiosulfonic Acid Formation (TSAF) comprises a step in which a compound of formula I is oxidized in the presence of a thiosulfate and an oxidizing agent selected from sodium persulfate, potassium persulfate, and ammonium persulfate to give a compound of formula II: wherein —R and wherein step (ii) Oxidative Coupling (OC) comprises a step in which a compound of formula IIa is oxidatively coupled to a compound of formula III, using an oxidising agent selected from sodium persulfate, potassium persulfate, or ammonium persulfate, to give a compound of formula IV: wherein: