Efficient synthesis of the pyrido[2,3,4-kl]acridin-4-one system common to several cytotoxic marine alkaloids

An efficient, four-step synthesis of the pyrido[2,3,4-kl]acridin-4-one system is described, using a Suzuki coupling of a 4-iodoquinoline and a oxidative demethylation of a dimethoxyquinoline containing an anilino unit with cobalt trifluoride as the key steps.