反应详情

Hydrazine hydrate (2 ml, ˜55%) was added to a suspension of 7-hydroxy-3-(4-methoxy-phenyl)-2-methyl-chromen-4-one (0.57 g, 2 mmol) in ethanol (15 ml) and the mixture heated under reflux for ˜5 hrs., to give a pale brown solution. The solution was allowed to cool and concentrated to a pale yellow solid, the solids were washed with water, to give the pyrazole as an off-white solid, dried in vacuo, (0.45 g). Sample was recrystallised from boiling toluene, to give the 4-[4-(4-methoxy-phenyl)-5-methyl-1H-pyrazol-3-yl]-benzene-1,3-diol as a pale brown crystalline solid, washed with hexane, dried in vacuo.

1. temperaturethe mixture heated
2. temperatureunder reflux for ˜5 hrs
3. custom, to give a pale brown solution
4. temperatureto cool
5. concentrationconcentrated to a pale yellow solid
6. washthe solids were washed with water