Cyclin-dependent　kinases　4/6　play　an　important　role　in　regulation　of　cell　cycle,　and　overexpress　in　a　variety　of　cancers.　Up　to　now,　new　CDK　inhibitors　still　need　to　be　developed　due　to　its　poor　selectivity.　Herein　we　report　a　novel　series　of　4-(2,3-dihydro-1H-benzo[d]　pyrrolo[1,2-a]　imidazole-7-yl)-N-(5-(piperazin-1-ylmethyl)　pyridine-2-yl)　pyrimidin-2-amine　anologues　as　potent　CDK　4/6　inhibitors　based　on　LY2835219　(Abemaciclib).　Compound　10d,　which　exhibits　approximate　potency　on　CDK4/6　(IC50　=　7.4/0.9　nM),　has　both　good　pharmacokinetic　characters　and　high　selectivity　on　CDK1　compared　with　LY2835219.　Overall,　compound　10d　could　be　a　promising　candidate　and　a　good　starting　point　as　anticancer　drugs.　(C)　2018　Elsevier　Ltd.　All　rights　reserved.