反应详情

5-Isopropyl-1H-pyrazole-3-carboxylic acid (WO 03/035065, page. 485, example 17b) (1.00 g, 6.49 mmol) was dissolved in a mixture of concentrated sulphuric acid (1.5 mL) and ethanol (25 mL) and the reaction mixture heated at reflux for 3 hours. The reaction mixture was cooled, poured into water, basified with 0.88 ammonia then extracted with ethyl acetate. The ethyl acetate was washed with brine, dried over magnesium sulphate and concentrated in vacuo to yield the title product, 514 mg (43%).

1. temperaturethe reaction mixture heated
2. temperatureat reflux for 3 hours
3. temperatureThe reaction mixture was cooled
4. extractionthen extracted with ethyl acetate
5. washThe ethyl acetate was washed with brine
6. dry with materialdried over magnesium sulphate
7. concentrationconcentrated in vacuo