反应详情

A mixture of 15.5 g of 5-bromo-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester and 14 g of potassium hydroxide in 300 ml of 3A ethanol was refluxed for 3 hours. The solution was poured into ice water and acidified with concentrated hydrochloric acid. The precipitated solid was collected by filtration and recrystallized from ethanol/water to afford 9.0 g of 5-bromo-1-phenyl-1H-pyrazole-4-carboxylic acid. Yield 64%. mp=218°-222° C.

1. temperaturewas refluxed for 3 hours
2. filtrationThe precipitated solid was collected by filtration
3. customrecrystallized from ethanol/water