Abstract
4-Phenyl-5, 8-quinolinediones (7, 8, 12, 13), 4-phenyl-5, 6-quinolinediones (9, 14), and 2-dialkylamino-4-phenyl-5, 8-quinolinediones (17, 18), were synthesized by oxidative demethylation of the corresponding 5, 8-dimethoxy- or 5, 6, 8-trimethoxy-4-phenylquinolines with cerium(IV) ammonium nitrate. Sulfur-containing quinolinequinones (21, 24) were prepared by oxidation of the corresponding 5, 8-dimethoxy- or 5, 6, 8-trimethoxy-2(1H)-quinolinethiones (20, 23).
