(S)-1-(2-Chloroacetyl)pyrrolidine-2-carboxamide-D3 is the deuterated form of (S)-1-(2-Chloroacetyl)pyrrolidine-2-carboxamide (C363865), which is used in the synthesis of Vildagliptin (V305000), an oral anti-diabetic drug, and its impurities (H971380) (Impurity A).