反应详情

A mixture of ethyl nitroacetate (80.0 g, 601 mmol) in ammonium hydroxide (25% NH3 in water, 400 mL) was stirred at room temperature for 3 days, and then the solution was concentrated by air-drying. The residue was dissolved in water (450 mL). To the solution was added 2,4-pentanedione (73.1 g, 730 mmol), pyridine (16.2 mL, 200 mmol) and acetic acid (11.4 mL, 200 mmol), and the mixture was stirred for an additional 7 days. The resulting precipitates were collected by filtration and dried under reduced pressure to give 35.0 g (35%) of the title compound as yellow solids: 1H-NMR (DMSO-d6) δ 12.44 (1H, br.s), 6.06 (1H, s), 2.19 (3H, s), 2.13 (3H, s).

1. concentrationthe solution was concentrated
2. customby air-drying
3. dissolutionThe residue was dissolved in water (450 mL)
4. stirringthe mixture was stirred for an additional 7 days
5. customThe resulting precipitates
6. filtrationwere collected by filtration
7. customdried under reduced pressure