反应详情

温度

5 °C

Into 200 ml of chlorosulfonic acid, there was added dropwise 50.4 g (0.3 mol) of Ethyl 1,3-dimethyl-5-pyrazole carboxylate under cooling at 5° C. or lower. After heating at 120° C. under stirring for 10 hours, the reaction mixture was poured into ice-water and extracted with ether. After washing with water and drying, evaporation of the solvent gave 49 g of crude 1,3-dimethyl-4-chlorosulfonyl-5-pyrazole carboxylic acid as a solid.

1. temperatureAfter heating at 120° C.
2. extractionextracted with ether
3. washAfter washing with water
4. customdrying
5. customevaporation of the solvent