反应详情

In the course of 15 minutes, 464 ml of 30% aqueous sodium hydroxide solution are added dropwise to a solution of 118.4 g of 2-isopropylthio-3-hydroxypyridine in 560 ml of dioxane. Then in the course of 2 hours, at a temperature of 80° C., 121 g of Freon-22 are introduced and the reaction mixture is stirred for a further 90 minutes. The reaction mixture is cooled to room temperature and then extracted with a mixture of 2500 ml of ice water and 1000 ml of methylene chloride and the phases are washed four times with 50 ml of methylene chloride each time and once with 100 ml of ice water. The combined organic phases are then dried over sodium sulfate and concentrated by evaporation in vacuo. Purification by silica gel chromatography with ethyl acetate/n-hexane 1:9 as eluant yields 105.7 g of 2-isopropylthio-3-difluoromethoxypyridine in the form of an oil having an nD21 of 1.5088.

1. extractionextracted with a mixture of 2500 ml of ice water and 1000 ml of methylene chloride
2. washthe phases are washed four times with 50 ml of methylene chloride each time
3. dry with materialThe combined organic phases are then dried over sodium sulfate
4. concentrationconcentrated by evaporation in vacuo
5. customPurification by silica gel chromatography with ethyl acetate/n-hexane 1:9 as eluant