反应详情

Under a nitrogen atmosphere, 3-fluoro-5-methoxyphenol (50-1) (15 g, 106 mmol) was diluted in DCE (150 mL, 0.7 M). To this solution NCS (15.5 g, 116 mmol) was added, and the reaction mixture was heated to reflux for 4 hours. The reaction was then cooled to room temperature and quenched with water (100 mL). The aqueous layer was then extracted with methylene chloride (3×50 mL). The organic extracts were dried over sodium sulfate and concentrated. Silica gel chromatography (1%-30% EtOAc/Hexanes) gave 2-chloro-3-fluoro-5-methoxyphenol (50-2) (6.7 g, 36%) and 4-chloro-3-fluoro-5-methoxyphenol (50-3) (2.8 g, 15%). LCMS (ES) m/z 177.2 (M)+. The starting material, 3-fluoro-5-methoxyphenol (50-1), was also recovered (4.3 g).

1. temperaturethe reaction mixture was heated
2. temperatureto reflux for 4 hours
3. customquenched with water (100 mL)
4. extractionThe aqueous layer was then extracted with methylene chloride (3×50 mL)
5. dry with materialThe organic extracts were dried over sodium sulfate
6. concentrationconcentrated