反应详情

温度

100 °C

744 ml of acetic anhydride was added to 77.97 g of 4-chloro-3-difloromethoxy-2-methylpyridine N-oxide (VI), which was heated at 100° C. for 4 hour. The solvent was distilled off under reduced pressure and 2N sodium hydroxide was added thereto to adjust to pH 11 and the resulting mixture was heated at 100° C. for 1 hour. The resulting mixture was extracted with chloroform and the resulting organic layer was washed with saturated salt water and dried over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent; chloroform:ethyl acetate=5:1) to obtain 23.11 g of 4-chloro-3-difluoromethoxy-2-hydroxymethylpyridine (VII).

1. distillationThe solvent was distilled off under reduced pressure and 2N sodium hydroxide
2. additionwas added
3. temperaturethe resulting mixture was heated at 100° C. for 1 hour
4. extractionThe resulting mixture was extracted with chloroform
5. washthe resulting organic layer was washed with saturated salt water
6. dry with materialdried over anhydrous sodium sulfate
7. distillationthe solvent was distilled off under reduced pressure
8. customThe resulting residue was purified by silica gel column chromatography (eluent; chloroform:ethyl acetate=5:1)