英文别名4-Chlorobutyric anhydride; 4-chloro-n-butyric anhydride; 4-chloro-butyric acid anhydride; γ-Chlor-buttersaeure-anhydrid; 4-Chlor-buttersaeure-anhydrid; 4-chlorobutanoyl 4-chlorobutanoate; Butanoic acid, 4-chloro-, anhydride; Butyric acid, 4-chloro-, anhydride; Levetiracetam Impurity 31; Levetiracetam Impurity 20 
