Discovery of 9-(1-phenoxyethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as oral PI3Kβ inhibitors, useful as antiplatelet agents.

Optimization of AZD6482 (2), the first antiplatelet PI3Kβ inhibitor evaluated in man, focused on improving the pharmacokinetic profile to a level compatible with once daily oral dosing as well as achieving adequate selectivity towards PI3Kα to minimize the risk for insulin resistance. Structure-based design and optimization of DMPK properties resulted in (R)-16, a novel, orally bioavailable PI3Kβ inhibitor with potent in vivo anti-thrombotic effect with excellent separation to bleeding risk and insulin resistance.