反应详情

A suspension of 23 g of ethyl hydrazine oxalate and 22 ml of triethylamine in 500 ml of toluene was stirred at room temperature for 15 minutes. 17 ml of methyl acetoacetate was added and the mixture was azeotroped for 1.5 hours. 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 19 g of 2-ethyl-5-methyl-2H-pyrazol-3-ol as an orange solid.

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