反应详情

A mixture of (E)-2-(3,3-diethoxyprop-1-enyl)-1-fluoro-3-nitrobenzene (63.5 mg, 0.22 mmol), 1,3-dibromo-5,5-dimethylhydantoin (63.5 mg, 0.222 mmol, Aldrich) and sulfuric acid, 95% (0.5 mL, 7.14 mmol) was stirred at room temperature for 4 h. Ice (5 g) was added and the mixture was extracted with EtOAc (2×20 mL). The combined organic extracts were washed with saturated NaCl (6 mL) and dried over Na2SO4. The solution was filtered and concentrated in vacuo to give the crude material as a yellow oil. The crude product was purified by silica gel chromatography eluting with 20% EtOAc/hexanes to give (E)-3-(4-bromo-2-fluoro-6-nitrophenyl)acrylaldehyde (46 mg, 0.168 mmol, 39.3% yield). 1H NMR (300 MHz, CDCl3) δ 7.47-7.58 (m, 1H) 7.58-7.71 (m, 1H) 8.10 (d, J=8.33 Hz, 1H) 8.15 (s, 1H) 9.50 (s, 1H). m/z (ESI, +ve ion) 273 (M+H)+.

1. extractionthe mixture was extracted with EtOAc (2×20 mL)
2. washThe combined organic extracts were washed with saturated NaCl (6 mL)
3. dry with materialdried over Na2SO4
4. filtrationThe solution was filtered
5. concentrationconcentrated in vacuo
6. customto give the crude material as a yellow oil
7. customThe crude product was purified by silica gel chromatography
8. washeluting with 20% EtOAc/hexanes