反应详情

温度

-78 °C

To a solution of 1,4-dibromo-2,5-difluorobenzene (5 g, 18.4 mmol) in anhydrous Et2O (60 mL) at −78° C. (dry ice/acetone bath) was added n-BuLi (7.72 mL, 19.31 mmol) dropwise. The reaction mixture was stirred at −78° C. for 30 minutes (min) (light yellow color), then TMSCl (2.59 mL, 20.23 mmol) was added. The reaction mixture was allowed to slowly warm to 20° C. and was stirred for 12 h. The reaction mixture was poured into a saturated (satd) aqueous (aq) ammonium chloride solution (NH4Cl; 150 mL), and the crude product was extracted with Et2O (3×). The combined organic layers were washed with satd aq NaCl, dried over MgSO4, filtered and concentrated (orange/brown oil). The residue was purified by column chromatography (silica gel (SiO2), eluting with hexanes) to afford the title compound as a colorless oil (4.17 g, 86%): 1H NMR (400 MHz, CDCl3) δ 7.20 (dd, J=7.1, 5.1 Hz, 1H), 7.09 (dd, J=8.0, 4.4 Hz, 1H), 0.31 (d, J=0.9 Hz, 9H); 19F NMR (376 MHz, CDCl3) δ −105.42, −115.48; EIMS m/z 266.

1. temperatureto slowly warm to 20° C.
2. stirringwas stirred for 12 h
3. extractionthe crude product was extracted with Et2O (3×)
4. washThe combined organic layers were washed with satd aq NaCl
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated (orange/brown oil)
8. customThe residue was purified by column chromatography (silica gel (SiO2), eluting with hexanes)