反应详情

A solution of 31.9 g of phenylhydrazine and 50.0 g of ethyl (ethoxymethylene)cyanoacetate (both reactants were obtained from Aldrich Chemical Company, Milwaukee, Wis.) disssolved in 500 ml of ethanol was refluxed for 6 hours. The mixture was allowed to stand for approximately 48 hours and was refluxed for an additional 8 hours. The reaction mixture was poured into ice water and the precipitated solid was collected by filtration. The solid was recrystallized from ethanol to afford 38.0 g of 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester. Yield 44%. mp=101°-103° C.

1. temperaturewas refluxed for 6 hours
2. temperaturewas refluxed for an additional 8 hours
3. filtrationthe precipitated solid was collected by filtration
4. customThe solid was recrystallized from ethanol