反应详情

To a solution of 3-methyl-1H-pyrazole-4-carboxylic acid (2.986 g, 23.68 mmol) in ethanol (20 ml) was added concentrated sulphuric acid (1 ml). The reaction was heated at reflux for 6 hours, cooled to room temperature, and then poured into a saturated aqueous solution of NaHCO3. The mixture was extracted with dichloromethane (3×50 ml) then the combined organic extracts dried over MgSO4 and concentrated in vacuo. The product crystallised on standing (2.105 g, 58% yield).

1. temperatureThe reaction was heated
2. temperatureat reflux for 6 hours
3. extractionThe mixture was extracted with dichloromethane (3×50 ml)
4. dry with materialthe combined organic extracts dried over MgSO4
5. concentrationconcentrated in vacuo
6. customThe product crystallised