反应详情

A solution of the compound (18.67 g, 64.31 mmol) obtained in step 1 and 1N aqueous sodium hydroxide solution (70.0 mL, 70 mmol) in ethanol (180 mL) was stirred at 70° C. for 14 hr, and concentrated under reduced pressure. To the residue were added water and 1N hydrochloric acid, and the precipitate was collected by filtration to give 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acid (16.87 g, 64.3 mmol, 100%) as a white powder.

1. concentrationconcentrated under reduced pressure
2. additionTo the residue were added water and 1N hydrochloric acid
3. filtrationthe precipitate was collected by filtration