反应详情

To a suspension of methyltriphenylphosphonium bromide (5.69 g, 15.91 mmol) in diethyl ether (80 mL) at room temperature was added n-BuLi (2.5 M in hexanes, 6.37 mL, 15.91 mmol) dropwise. The reaction immediately turned bright orange and the resulting solution was stirred for 35 min at room temperature after which time a solution of l-(2-bromo-5-fluorophenyl)ethanone (3.14 g, 14.47 mmol) in diethyl ether (20 mL) was added dropwise. The reaction lost the bright yellow color and became almost completely white with a significant amount of white precipitate, the reaction was stirred for 89 h after it was quenched by addition of water and extracted with diethyl ether (3×), the combined organic layers were dried over anhydrous MgSO4, filtered and concentrated in vacuo. The resulting crude material was purified by column chromatography (SiO2, 0-5% Diethyl Ether/Hexanes) to afford 1-bromo-4-fluoro-2-(prop-1-en-2-yl)benzene. 1H NMR (400 MHz, CDCl3) δ ppm 7.49 (dd, J=8.8, 5.3 Hz, 1H), 6.92 (dd, J=9.0, 3.1 Hz, 1H), 6.85 (td, J=8.3, 3.1 Hz, 1H), 5.24 (t, J=1.7 Hz, 1H), 4.96 (s, 1H), 2.08 (d, J=1.4 Hz, 3H).

1. customThe reaction immediately turned bright orange
2. additionwas added dropwise
3. customwas quenched by addition of water
4. extractionextracted with diethyl ether (3×)
5. dry with materialthe combined organic layers were dried over anhydrous MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe resulting crude material was purified by column chromatography (SiO2, 0-5% Diethyl Ether/Hexanes)