英文别名Pyrido[2,3-d]pyrimidine-6-carboxylic acid, 8-cyclopentyl-2-[[5-[4-[(1,1-dimethylethoxy)carbonyl]-1-piperazinyl]-2-pyridinyl]amino]-7,8-dihydro-5-methyl-7-oxo-, ethyl ester; ethyl 8-cyclopentyl-5-methyl-2-[[5-[4-[(2-methylpropan-2-yl)oxycarbonyl]piperazin-1-yl]pyridin-2-yl]amino]-7-oxopyrido[2,3-d]pyrimidine-6-carboxylate; Palbociclib Impurity 119