反应详情

A suspension of 3.9 g of ethyl hydrazine oxalate and 3.6 ml of triethylamine in 80 ml of toluene was stirred at room temperature for 15 min. 2.8 ml of methyl acetoacetate was added and the mixture was azeotroped for 1.5 h. The mixture was evaporated and the residue was purified by flash chromatography on silica gel using dichloromethane/methanol (97:3) for the elution to give 3.1 g of 2-ethyl-5-methyl-2H-pyrazol-3-ol as an orange solid.

1. customthe mixture was azeotroped for 1.5 h
2. customThe mixture was evaporated
3. customthe residue was purified by flash chromatography on silica gel
4. washfor the elution