Design, synthesis and biological evaluation of novel 4-phenoxyquinoline derivatives containing 3-oxo-3,4-dihydroquinoxaline moiety as c-Met kinase inhibitors

A series of novel 4-phenoxyquinoline derivatives containing 3-oxo-3,4-dihydroquinoxaline moiety were synthesized and evaluated for their c-Met kinase inhibitory activity and antiproliferative activity against five cancer cell lines (HT-29, H460, A549, MKN-45 and U87MG) in vitro. Most of the compounds exhibited moderate-to-significant cytotoxicity as compared with foretinib. The most promising compound 41 (with c-Met IC50 value of 0.90nM) showed remarkable cytotoxicity against HT-29, H460, A549, MKN-45 and U87MG cell lines with IC50 values of 0.06μM, 0.05μM, 0.18μM, 0.023μM and 0.66μM, respectively, and thus it was 1.22- to 3.50-fold more potent than foretinib. Their preliminary structure-activity relationships (SARs) studies indicate that electron-withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity.