反应详情

温度

0 °C

(4-Bromo-3-methylphenyl)methanol (14.4 g, 71.6 mmol) is dissolved in anhydrous CH2Cl2 (150 mL) and CBr4 (26.1 g, 79.0 mmol) is added. The reaction mixture is cooled to 0° C. and PPh3 (20.7 g, 79.0 mmol) is added in small portions. The reaction mixture is stirred 2 h and the triphenylphosphine oxide that forms is filtered off and the solvent removed in vacuo. The resulting semi solid is filtered on a silica gel pad and rinsed with hexane/EtOAc (9:1) to provide the expected product 1-Bromo-4-(bromomethyl)-2-methylbenzene as a clear oil contaminated with bromoform which is used directly in the next step. 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 4.39-4.44 (m, 3H) 7.07 (dd, J=8.20, 2.34 Hz, 1H) 7.26 (t, J=1.17 Hz, 1H) 7.49 (d, J=8.20 Hz, 1H)

1. filtrationthe triphenylphosphine oxide that forms is filtered off
2. customthe solvent removed in vacuo
3. filtrationThe resulting semi solid is filtered on a silica gel pad
4. washrinsed with hexane/EtOAc (9:1)