Inhibitors of VEGF receptors-1 and -2 based on the 2-((pyridin-4-yl)ethyl)pyridine template

We have developed a series of novel potent ((pyridin-4-yl)ethyl)pyridine derivatives active against kinases VEGFR-1 and -2. Both specific and dual ATP-competitive inhibitors of VEGFR-2 were identified. Kinase selectivity could be controlled by varying the arylamino substituent at the 1,3,4-oxadiazole ring. Most specific molecules displayed >10-fold selectivity for VEGFR-2 over VEGFR-1. Compound activities in both in vitro and cell-based assays (IC50<100nM) were similar to those of reported clinical and development candidates, including PTK787 (Vatalanib™). High permeability of the active compounds across Caco-2 cell monolayer (>30×10−5cm/min) is indicative of their potential for intestinal absorption upon oral administration.