反应详情

To a solution of ethyl-3,4-dimethoxybenzoylacetate (1 g, 4 mmol), (Heterocycles 1979, 13, 239), in ethanol (5 ml) containing hydrazine hydrate (192 μl, 4 mmol) was stirred for 30 minutes at ambient temperature followed by 40 minutes being heated at reflux. After cooling at ambient temperature, the mixture was concentrated to half the volume and ether (10 ml) was added. After trituration, the solid was collected by filtration, washed with ether and dried under vacuum to give 3-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-5-one (521 mg, 60%).

1. waitfollowed by 40 minutes
2. temperaturebeing heated
3. temperatureat reflux
4. temperatureAfter cooling at ambient temperature
5. concentrationthe mixture was concentrated to half the volume and ether (10 ml)
6. additionwas added
7. filtrationAfter trituration, the solid was collected by filtration
8. washwashed with ether
9. customdried under vacuum