C([O:3][C:4](=O)[CH2:5][C:6]1([C:12]([O:14]CC)=O)[CH2:10][C:9](=[O:11])[NH:8][CH2:7]1)C.[CH3:18][NH2:19]>>[CH3:18][N:19]1[C:4](=[O:3])[CH2:5][C:6]2([CH2:10][C:9](=[O:11])[NH:8][CH2:7]2)[C:12]1=[O:14]A solution of 20.3 g (0.084 mole) 3-ethoxycarbonyl-5-oxo-3-pyrrolidineacetic acid ethyl ester [J. Org. Chem. 46, 2757 (1981)] in 40 ml of 40% aqueous methylamine was stirred at room temperature overnight, then placed in an oil bath and gradually heated to 220° C. over 30 minutes allowing volatiles to distill from the open flask. The crude product was crystallized from ethanol to afford 12.56 g of the title compound, mp 201°-204° C.
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