Cerium (IV) ammonium nitrate (CAN)-mediated regioselective synthesis and anticancer activity of 6-substituted 5,8-dimethoxy-1,4-naphthoquinone

6-Substituted 5, 8-O-dimethyl-1, 4-naphthoquinones (6-DMNQ) were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN using EtOAc/H2O as the solvent system in comparatively high yields. The majority of the prepared 6-DMNQ displayed selective cytotoxic activities toward HCT-15 cells, together with no apparent cytotoxicities toward the normal cells.