The 2,7-naphthyridone scaffold has been proposed as a novel lead structure ofMETinhibitors by our group. To broaden the application of this new scaffold, a series of 8-amino-substituted 2-phenyl-2,7-naphthyridin-1(2H)-one derivatives were designed and synthesized. Preliminary biological screening resulted in the discovery of a new lead of c-Kit and VEGFR-2 kinase inhibitors. Compound 9k exhibited excellent c-Kit inhibitory activity, with an IC50 value of 8.5 nM, i.e., it is 38.8-fold more potent than compound 3 (IC50 of 329.6 nM). Moreover, the...