反应详情

Add n-butyl lithium (13 mL, 1.6M, 20.76 mmol) to 1-bromo-3-fluoro-5-propoxybenzene (4.40 g, 18.88 mmol) in tetrahydrofuran (100 mL) cooled in a dry ice/acetone bath over 45 minutes, maintaining the internal temperature <−70°. Stir 30 minutes and add N,N-dimethylformamide (2.76 g, 37.75 mmol). Stir 30 minutes and remove cold bath. After 1 hour, quench with saturated aqueous ammonium chloride. Wash organic layer with water and saturated aqueous sodium chloride. Dry (sodium sulfate), filter and concentrate to an oil. Purify on 120 g silica gel eluting with 0 to 10% ethyl acetate in hexanes to give 2.26 g (65.7%) of the desired compound as an oil.

1. temperaturecooled in a dry ice/acetone bath over 45 minutes
2. temperaturemaintaining the internal temperature <−70°
3. stirringStir 30 minutes
4. customremove cold bath
5. waitAfter 1 hour
6. customquench with saturated aqueous ammonium chloride
7. dry with materialDry (sodium sulfate)
8. filtrationfilter
9. concentrationconcentrate to an oil
10. customPurify on 120 g silica gel eluting with 0 to 10% ethyl acetate in hexanes