C[N:2]([CH:4]=[C:5]([C:10](=[O:14])[CH2:11][O:12][CH3:13])[C:6]([O:8][CH3:9])=[O:7])C.Cl.NO>CO>[CH3:13][O:12][CH2:11][C:10]1[O:14][N:2]=[CH:4][C:5]=1[C:6]([O:8][CH3:9])=[O:7]To a solution of methyl 2-[(dimethylamino)methylene]-4-methoxy-3-oxobutanoate (Preparation 43, 5.2 g, 26 mmol) in methanol (55 ml) was added hydroxylamine hydrochloride (1.8 g, 25.8 mmol) and the reaction stirred at reflux for 7 hours. The reaction was concentrated in vacuo. The solid residue was purified by trituration with ethyl acetate to afford the title compound as a solid (3.6 g, 18% yield).
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