反应详情

Dissolve p-trifluoromethylpropiophenone (5.130 g, 25.120 mmol) in hydrogen bromide (30.00 mL) and acetic acid (20 mL). Add bromine (1.23 mL, 23.864 mmol) in acetic acid (25 mL) drop-wise over 30 minutes. Stir the reaction mixture for 48 hours, and dilute the reaction mixture with water (1 L) and EtOAc (250 mL). Add solid sodium carbonate portion-wise to adjust the pH to ˜7 allowing the gas evolution to cease between additions. Extract the resulting mixture with EtOAc (2×250 mL). Dry the organic extracts over Na2SO4. Filter; collect the filtrate; and concentrate the filtrate under reduced pressure to give the title compound as a clear oil (7.140 g, 100% crude yield). 1H NMR (399.83 MHz, d6-DMSO) δ 8.20 (dd, J=0.7, 8.8 Hz, 2H), 7.92-7.90 (m, 2H), 5.85 (q, J=6.5 Hz, 1H), 1.78 (d, J=6.5 Hz, 3H).

1. extractionExtract the resulting mixture with EtOAc (2×250 mL)
2. dry with materialDry the organic extracts over Na2SO4
3. filtrationFilter
4. customcollect the filtrate
5. concentrationand concentrate the filtrate under reduced pressure