Design, Synthesis and Biological Evaluation of 6,7-Disubstituted-4-phenoxyquinoline Derivatives Bearing Pyridazinone Moiety as c-Met Inhibitors

Deregulation of the receptor tyrosine kinase mesenchymal epithelial transition factor (MET) has been implicated in several human cancers and is an attractive target for small molecule drug discovery. Herein, a series of 6,7-disubstituted-4-phenoxyquinoline derivatives bearing pyridazinone derivatives were designed, synthesized and evaluated for their enzymatic inhibitory activity against c-Met kinase and cellular potency against A549, HepG2, and MCF-7 cell lines. Eight of them are equal to more active than positive control Foretinib against one or more cell lines and enzyme. The most promising compound 53 showed superior activity to Foretinib, which possessed excellent c-Met kinase inhibition on a singledigital nanomolar level (IC(50) = 0.6 nM), and cancer cells of A549 (IC(50) = 0.003 µM), HepG2 (IC(50) = 0.49 µM) and MCF-7 cells (IC(50) = 0.006 µM). The result of AO single staining indicated that compound 53 could induce remarkable apoptosis of HepG2 cell.