Design, Synthesis and Anticancer Activity of 4-Morpholinothieno[3,2-<i>d</i>]pyrimidine Derivatives Bearing Arylmethylene Hydrazine Moiety

Three series of 4-morpholinothieno3,2-d]pyrimidine derivatives containing arylmethylene hydrazine moiety (11a-f, 13a-k and 15a-h) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed. The synthesized compounds were evaluated for their cytotoxicity against three cancer cell lines (H460, HT-29, MDA-MB-231). Most of them exhibited moderate to significant cytotoxicity and high-selectivity against one or more cell lines, especially compounds 11c, 13b, 15f and 15g possessing dramatically increased cytotoxicity as compared with the positive controls, which were further evaluated for six other cancer cell lines and one normal cell line. The most promising compound 11c, bearing 3,4-methylenedioxy phenyl group, showed remarkable cytotoxicity against H460, HT-29 and MDA-MB-231 cell lines with IC50 values of 0.003?μM, 0.42?μM and 0.74?μM, which was 1.6- to 290-fold more potent than GDC-0941.