Discovery of (2<i>S</i>)‑8-[(3<i>R</i>)‑3-Methylmorpholin-4-yl]-1-(3-methyl-2-oxobutyl)-2-(trifluoromethyl)-3,4-dihydro‑2<i>H</i>‑pyrimido[1,2‑<i>a</i>]pyrimidin-6-one: A Novel Potent and Selective Inhibitor of Vps34 for the Treatment of Solid Tumors

Vps34 (the human class III phosphoinositide 3-kinase) is a lipid kinase involved in vesicle trafficking and autophagy and therefore constitutes an interesting target for cancer treatment. Because of the lack of specific Vps34 kinase inhibitors, we aimed to identify such compounds to further validate the role of this lipid kinase in cancer maintenance and progression. Herein, we report the discovery of a series of tetrahydropyrimido­pyrimidinone derivatives. Starting with hit compound <b>1a</b>, medicinal chemistry optimization led to compound <b>31</b>. This molecule displays potent activity, an exquisite selectivity for Vps34 with excellent properties. The X-ray crystal structure of compound <b>31</b> in human Vps34 illustrates how the unique molecular features of the morpholine synthon bestows selectivity against class I PI3Ks. This molecule exhibits suitable in vivo mouse PK parameters and induces a sustained inhibition of Vps34 upon acute administration. Compound <b>31</b> constitutes an optimized Vps34 inhibitor that could be used to investigate human cancer biology