反应详情

4-Chloro-3-fluorobenzaldehyde (13 g, 82 mmol) and ammonium acetate (14.6 g, 189 mmol) were dissolved in acetic acid (150 ml) and nitromethane (12.6 ml, 234 mmol) was added. The solution was heated to reflux for 1.5 h. After cooling to RT water (120 ml) was added. A solid precipitated. The reaction was extracted three times with methylene chloride. The combined organic layers were washed with water and sat. aq. NaCl solution, dried over magnesium sulfate, filtered and the solvent was removed in vacuo. The residue was purified by flash column chromatography (Ethyl acetate/cyclohexane:1/4). The crude product was suspended in heptane, filtered and dried to yield 1-chloro-2-fluoro-4-(2-nitro-vinyl)-benzene (10.9 g, 66%) as a light yellow solid. 1H NMR (CDCl3, 300 MHz): δ 7.29 (d, J=7.8 Hz, 1H), 7.33 (d, J=9.3 Hz, 1H), 7.50 (t, J=7.5H7, 1H), 7.54 (d, J=13.6 Hz, 1H), 7.92 (d, J=13.6 Hz, 1H).

1. temperatureThe solution was heated
2. temperatureto reflux for 1.5 h
3. additionwas added
4. customA solid precipitated
5. extractionThe reaction was extracted three times with methylene chloride
6. washThe combined organic layers were washed with water and sat. aq. NaCl solution
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. customthe solvent was removed in vacuo
10. customThe residue was purified by flash column chromatography (Ethyl acetate/cyclohexane:1/4)
11. filtrationfiltered
12. customdried