反应详情

To a solution of 1-tert-butyl-5-chloro-1H-pyrazole-4-carboxylic acid ethyl ester (5 g, 21.7 mmol) in methanol (50 mL) and water (50 mL) was added LiOH (0.63 g, 26.3 mmol). The reaction mixture was stirred at reflux overnight and then concentrated under reduced pressure to remove the methanol. The residue was diluted with water, acidified to pH 2 with concentrated HCl (4 mL), and extracted with ethyl acetate. The organic extracts were evaporated in vacuo to give 1-tert-butyl-5-chloro-1H-pyrazole-4-carboxylic acid (4 g, 91%) which was used without further purification.

1. temperatureat reflux overnight
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 extracts were evaporated in vacuo