The formation of 3-chloro-10-methylphenothiazine(IV) by reductive chlorination of 10- methylphenothiazine-S-oxide(I) has been confirmed by synthesis of IV. Under similar conditions l0-(3-diethylaminopropyl)-phenothiazine-5-oxide gave 3 (?)-chloro-lO-(3- diethylamixiopropyl)-phenothiazine while l0-(3-diethylaminopropyl)-phenothiazine-~, 5- dioxide gave a dichlorophenothiazine. 3, 7-Dichloro-lO-methylphenothiazine-5-oxide ...
