Palladium-Catalyzed Amination of 2,3-Dichloro-1,4-naphthoquinone with Nitroarylamines

A convenient one-step synthesis of 2-[(nitroaryl)amino]-3-chloro-1,4-naphthoquinones is reported. The direct amination of 2,3-dichloro-1,4-naphthoquinone with nitro-substituted aryl amines is catalyzed by PdCl2(dppf)/dppf in the presence of t-BuONa as base to yield 2-[(nitroaryl)amino]-3-chloro-1,4-naphthoquinones, several of which were previously unavailable. Traces of the 2,3-di[(nitroaryl)amino]-1,4-naphthoquinones were detected as side products.