反应详情

To a solution of 4-trifluoromethoxybenzaldehyde (150 g, 0.79 mol) in a mixture of TFA (400 mL) and H2SO4 (80 mL) was added at 40–45° C. N-bromosuccinimide (281 g, 1.579 mol) in equal portion over 2 hours. The reaction mixture was stirred at 40–45° C. overnight, poured into ice-water and extracted with CH2Cl2. The organic layer was washed with water then treated with saturated NaHCO3 (800 mL) for 30 minutes. The layers were separated and the organic layer further washed with water and brine, dried over MgSO4, filtered-and evaporated. The residue was triturated with hexane and filtered. After evaporation of the solvent, the residue was distilled to give 3-bromo-4-trifluoromethoxybenzaldehyde (150.2 g, 60° C., 0.3 mm/Hg, 70%). 1H NMR (300 MHz; CDCl3): δ 7.49 (dd, J1=1.8 Hz and J2=8.7 Hz, 1H), 7.88 (dd, J1=2.1 Hz and j2=8.4 Hz, 1H), 8.17 (d, J=1.8 Hz, 1H), 9.97 (s, 1H).

1. additionwas added at 40–45° C
2. extractionextracted with CH2Cl2
3. washThe organic layer was washed with water
4. additionthen treated with saturated NaHCO3 (800 mL) for 30 minutes
5. customThe layers were separated
6. washthe organic layer further washed with water and brine
7. dry with materialdried over MgSO4
8. filtrationfiltered-
9. customevaporated
10. customThe residue was triturated with hexane
11. filtrationfiltered
12. customAfter evaporation of the solvent
13. distillationthe residue was distilled