反应详情

A solution of ethyl 1-methyl-1H-pyrazole-4-carboxylate (20.2 g, 131 mmol) and NaOH (6.3 g, 158 mmol) in 200 mL absolute ethanol was refluxed for 2 h and stirring was continued at RT for 18 h. After that, the solvent was removed in vacuo. The residue was dissolved in water. The aq solution was washed with ether and acidified with concentrated HCl. The solid was filtered, washed with water and air-dried to give 14.2 g of 1-methyl-1H-pyrazole-4-carboxylic acid in 86% yield.

1. customAfter that, the solvent was removed in vacuo
2. dissolutionThe residue was dissolved in water
3. washThe aq solution was washed with ether
4. filtrationThe solid was filtered
5. washwashed with water
6. customair-dried