英文别名3-(2-chloro-4-(cyclopentylamino)pyrimidin-5-yl)but-2-enoic acid; Palbociclib Impurity 132; 2-Butenoic acid, 3-[2-chloro-4-(cyclopentylamino)-5-pyrimidinyl]-; (E)-3-[2-Chloro-4-(cyclopentylamino)-5-pyrimidinyl]-2-butenoic Acid; (Z)-3-(2-chloro-4-(cyclopentylamino)pyrimidin-5-yl)but-2-enoic acid; Palbociclib Impurity 71 
