英文别名(R)-Sitagliptin N-Boc-Methyl-Ester Impurity; (3R)-tert-Butoxycarbonylamino-4-(2,4,5-trifluoro-phenyl)-butyric acid methyl ester; Methyl (R)-β-(Boc-amino)-2,4,5-F3-benzenebutanoate; Sitagliptin Impurity 54; 3-(R)-Boc-amino-4-(2,4,5-trifluoro-phenyl)butyric acid methyl ester