Design and synthesis of 4-(2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazol-7-yl)-N-(5-(piperazin-1-ylmethyl)pyridine-2-yl)pyrimidin-2-amine as a highly potent and selective cyclin-dependent kinases 4 and 6 inhibitors and the discovery of structure-activity relationships

Abstract 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-1 H -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 (IC 50  = 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.