Synthesis and antiproliferative activity of 6,7-disubstituted-4-phenoxyquinoline derivatives bearing the 2-oxo-4-chloro-1,2-dihydroquinoline-3-carboxamide moiety.

A series of 6,7-disubstituted-4-phenoxyquinoline derivatives bearing the 2-oxo-4-chloro-1,2-dihydroquinoline-3-carboxamide moiety were synthesized, and evaluated for their antiproliferative activity against 5 cancer cell lines (H460, HT-29, MKN-45, A549, and U87MG). Most compounds showed moderate to excellent potency, and compared to foretinib, the most promising analog 42 (c-Met/Flt-3 IC50=1.21/2.15nM) showed a 6.1-fold increase in activity against H460 cell line in vitro. The enzymatic assays (c-Met, VEGFR-2, Flt-3, PDGFR-β, c-Kit, and EGFR) of compound 42 were evaluated in vitro. Docking analysis showed that compound 42 could form three hydrogen bonds with c-Met. Structure-activity relationship studies indicated that a more water-soluble cyclic tertiary amine and electron-withdrawing groups at 4-position of the phenyl ring contribute to the antitumour activity.