反应详情

温度

70 °C

A mixture of 3-amino-5-pyrazolone (3.57 g; 36.1 mmole) and 2-[(3-nitrophenyl)methylene]-3-oxobutanoic acid, 1-methylethyl ester (10.0 g; 36.1 mmole) in dry dimethylformamide (30 ml) was heated at 70° C. under argon for 24 hours. The reaction mixture was allowed to cool to room temperature and then diluted with ether. The resultant precipitate was filtered off and recrystallized from isopropanol to provide the title compound in crystalline form (4.23 g; melting point 254°-256° C.).

1. temperatureto cool to room temperature
2. filtrationThe resultant precipitate was filtered off
3. customrecrystallized from isopropanol