Réaction #48054

Équation de réaction

water

4-Chloro-3-fluorobenzaldehyde

ammonium acetate

nitromethane

→

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

Rendement 66.0%

Solvants

acetic acid

Conditions de réaction

Traitement

1. 1
   TempératureThe solution was heated
2. 2
   Températureto reflux for 1.5 h
3. 3
   workup.ADDITIONwas added
4. 4
   AutreA solid precipitated
5. 5
   ExtractionThe reaction was extracted three times with methylene chloride
6. 6
   LavageThe combined organic layers were washed with water and sat. aq. NaCl solution
7. 7
   Séchagedried over magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Autrethe solvent was removed in vacuo
10. 10
    AutreThe residue was purified by flash column chromatography (Ethyl acetate/cyclohexane:1/4)
11. 11
    Filtrationfiltered
12. 12
    Autredried

Mode opératoire

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).

Source