反应详情

11.6 g of the 3-(4-chloro-2-fluorophenyl)-5-difluoromethoxy-1H-pyrazole (purity 86%) obtained in step 1.2 were initially charged in 100 ml of toluene. 6.2 g of dimethyl sulfate were added dropwise, and the mixture was heated at reflux for 3 h. After cooling, 25 ml of saturated aqueous NH4Cl solution were added, the mixture was stirred for 1 h and the organic phase was separated off and washed with water until neutral. Drying over Na2SO4 and concentration gave 11.3 g of 3-(4-chloro-2-fluorophenyl)-5-difluoromethoxy-1-methyl-1H-pyrazole as an oil of a purity of 82.4% (GC). Yield: 88.6%

1. temperaturethe mixture was heated
2. temperatureat reflux for 3 h
3. temperatureAfter cooling
4. customthe organic phase was separated off
5. washwashed with water until neutral
6. dry with materialDrying over Na2SO4 and concentration