[CH3:1][N:2]([C:4](=[O:7])[CH2:5][CH3:6])[NH2:3].O=[C:9]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[C:10]([O:12][CH2:13][CH3:14])=[O:11]>C1(C)C=CC=CC=1>[CH3:1][N:2]([C:4](=[O:7])[CH2:5][CH3:6])[N:3]=[C:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[C:15]([O:17][CH2:18][CH3:19])=[O:16]A solution of N-methylpropionohydrazide (18.78 g, 183.9 mmol) and diethyl ketomalonate (56.1 mL, 368 mmol) in toluene (136 mL) was refluxed with a Dean-Stark trap for 4 hours. The reaction mixture was concentrated under reduced pressure to give the crude material that was purified by silica gel flash column chromatography (100% hexanes to 5 to 10% EtOAc in hexanes) to afford 23 g (49%) of the desired product.
Wird geladen…