16395-57-6

4931-66-2

16395-57-6

GENERAL METHOD: L-Pyroglutamic acid methyl ester (10 mmol) was dissolved in a mixed NH3[aq]/N2H4[aq] solution (50 mL) at room temperature and the reaction was stirred for 12 hours. Subsequently, the reaction mixture was allowed to stand at -10 °C for 24 h to promote crystallization. The resulting crystals were washed sequentially with ethanol and ether and dried with anhydrous MgSO4. The crude product was purified by fast column chromatography on silica gel with the eluent methanol/dichloromethane (1:6, v/v), resulting in the pure (S)-5-oxopyrrolidine-2-carboxamide in white solid form.