Reaktion #48054

Reaktionsgleichung

water

4-Chloro-3-fluorobenzaldehyde

ammonium acetate

nitromethane

→

1-chloro-2-fluoro-4-(2-nitro-vinyl)-benzene

Ausbeute 66.0%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution was heated
2. 2
   Temperaturto reflux for 1.5 h
3. 3
   workup.ADDITIONwas added
4. 4
   SonstigeA solid precipitated
5. 5
   ExtraktionThe reaction was extracted three times with methylene chloride
6. 6
   WaschenThe combined organic layers were washed with water and sat. aq. NaCl solution
7. 7
   Trocknendried over magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigethe solvent was removed in vacuo
10. 10
    SonstigeThe residue was purified by flash column chromatography (Ethyl acetate/cyclohexane:1/4)
11. 11
    Filtrationfiltered
12. 12
    Sonstigedried

Vorschrift

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).

Quelle