反应详情

To a stirred solution of 15.7 grams (0.634 mole) of 2,3,5,6-tetrafluoro-4-trifluoromethylphenylhydrazine in 40 mL of anhydrous ethanol was added 10.7 grams (0.634 mole) of ethyl 2-cyano-3-ethoxyacrylate. The reaction mixture was heated at reflux for 21 hours, then cooled, and the solvent was removed by distillation under reduced pressure, leaving a residue. This residue was suspended in 80 mL of a 50:50 mixture of diethyl ether/n-pentane. A solid formed and was removed by filtration to yield 20.4 grams of ethyl 5-amino-1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)pyrazol-4-ylcarboxylate, m.p. 166-168° C. The nmr spectrum was consistent with the proposed structure.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 21 hours
3. temperaturecooled
4. customthe solvent was removed by distillation under reduced pressure
5. customleaving a residue
6. customA solid formed
7. customwas removed by filtration