A　novel　series　of　4-aryl-5,7-dihydro-6H-pyrrolo[2,3-d]pyrimidin-6-one　derivatives　were　designed　as　a　phosphoinositide　3-kinase　alpha　(PI3K　alpha)　inhibitor　by　scaffold　hopping.　The　target　compounds,　characterized　by　H-1-NMR　C-13-NMR　and　high　resolution　(HR)-MS,　were　synthesized　from　diethyl　malonate　and　ethyl　chloroacetate　by　nucleophilic　substitution,　ring-closure,　chlorination　and　Suzuki　reaction,　etc.　The　biological　activities　were　evaluated　with　cytotoxic　activity　in　vitro　on　Uppsala　87　Malignant　Glioma　(U87MG)　and　prostate　cancer-3　(PC-3)　by　Cell　Counting　Kit-8　(CCK-8).　The　results　showed　that　compound　9c　displayed　the　higher　inhibition　than　the　positive　control　PI-103,　and　high　PI3K　alpha　inhibitory　activity　with　IC50　of　113　+/-　9　nM　in　the　same　order　of　magnitude　as　BEZ235.　In　addition,　the　LogK(ow)　values　and　molecular　docking　studies　were　performed　to　further　investigate　the　drug-like　properties　of　target　compounds　and　interactions　between　9c　and　PI3K　alpha.