Palladium Catalyzed Transformation and Antimicrobial Screening of Novel Angular Azaphenothiazines

Abstract

Base mediated condensation reaction between 2-amino-5-bromopyrazine-3[4H]-thione and 7-chloro-5,8-quinolinequinone under anhydrous condition gave 9-bromo-1,8,11-triaza-5H-benzo[ a]phenothiazin-5-one. Palladium catalyzed cross-coupling reaction between 9-bromo-1,8,11-triaza-5H-benzo[a]phenothiazin-5-one and four arylated halogeno compounds utilizing Heck-Mizoroki protocol furnished 6-substituted derivatives of the angular tetracyclic heterocycle. Structures were assigned based on spectroscopic and elemental analytical data. Antimicrobial screening of these compounds showed they were biologically active.