Novel benzoquinoline derivatives via unpredicted condensation of ethyl propiolate and naphthylamines: Synthesis and topoisomerase inhibition activity

Abstract An unpredicted condensation of naphthylamine with two molecules of ethyl propiolate yields directly carbethoxy benzoquinoline in high yield. Some benzoquinoline carboxamide derivatives with protonatable side chains were then synthesized and evaluated for antiproliferative activity on human tumor cell lines. The most active compound ( 7a ) demonstrated to intercalate into DNA and to inhibit the relaxation activity mediated by topoisomerase II.