Synthesis of Some Derivatives of Benzophenothiazinone Of Pharmaceutical Interests Via Nickel Catalysed Grignard Couplings

Abstract

Some derivatives of 6-chlorobenzo[a]phenothiazin-5-one were synthesized via nickel catalyzed Grignard couplings. The parent compound 6-chlorobenzo[a]phenothiazin-5-one was prepared by refluxing a mixture of 2-aminobenzenethiol and 2,3-dichloro-1,4-napthoquinone in anhydrous potassium acetate in benzene/ethanol to obtain a deep orange crystalline powder in an excellent yield  after work-up. The structures of new prepared derivatives were determined by elemental analysis and spectroscopic methods (nmr, ir and ms).