英文别名(S)2-(2-Oxo pyrrolidin-1-yl)-Butiric acid methyl ester; Levetiracetam-6; Levetiracetam Impurity 16; (S)-methyl 2-(2-oxopyrrolidin-1-yl)-2-butanoate; 1-Pyrrolidineacetic acid, α-ethyl-2-oxo-, methyl ester, (αS)-; Levetiracetam impurities517; Levetiracetam impuritiesE; (2S)-(2-OXOPYRROLIDIN-1-YL)BUTYRIC ACID, METHYL ESTER 
