Discovery of novel 4-(2-pyrimidinylamino)benzamide derivatives as highly potent and orally available hedgehog signaling pathway inhibitors.

A series of novel hedgehog signaling pathway inhibitors have been designed by structural modification based on the former reported scaffold of 4-(2-pyrimidinylamino)benzamide. The SAR for this series was described and many derivatives showed potent inhibitory activity. Among these compounds, compounds 12af and 12bf were identified to have high potency and optimal PK profiles. Although both of compounds 12af and 12bf did not show strong antitumor efficacy in LS-174T nude mice model, they were promising candidates as Hh signaling inhibitors due to great potency against Hh signaling pathway and outstanding PK properties, deserving further evaluation in other Hh signaling operative tumor models.