反应详情

To a solution of 5-chloro-1-cyclobutyl-1H-pyrazole-4-carboxylic acid ethyl ester (182 mg, 0.79 mmol) in methanol (8 mL) and water (8 mL) was added LiOH (23 mg, 0.96 mmol). The reaction mixture was stirred at reflux for 4 hours and then concentrated under reduced pressure to remove the methanol. The residue was diluted with water, acidified to pH 2 with concentrated HCl and extracted with ethyl acetate. The organic layer was evaporated in vacuo to give 5-chloro-1-cyclobutyl-1H-pyrazole-4-carboxylic acid (148 mg, 94%) which was used without further purification.

1. temperatureat reflux for 4 hours
2. concentrationconcentrated under reduced pressure
3. customto remove the methanol
4. additionThe residue was diluted with water
5. extractionextracted with ethyl acetate
6. customThe organic layer was evaporated in vacuo