Réaction #8491

Équation de réaction

NaCl

Sodium hydride

diethyl-2-cyano-4-fluorobenzyl phosphonate

4-Fluorobenzaldehyde

→

compound

Rendement 23.2%

2-[2(4-Fluorophenyl)ethenyl]-5-fluorobenzonitrile

Rendement 23.2%

Solvants

DMF

H2O

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGAfter stirring for 18 h
2. 2
   Extractionthe resulting mixture was extracted with EtOAc (2×100 mL)
3. 3
   LavageThe combined organic layers were washed with 1N NaOH (1×100 mL) and H2O (2×100 mL)
4. 4
   Séchagedried (anhyd. Na2SO4)
5. 5
   Autrerotary evaporated
6. 6
   Température(>100° C., heat gun)
7. 7
   AutreThe crude, dark-red crystalline/oil (7.49 g, 82.7%) was chromatographed twice on silica gel (50×250 mm, dry pack)
8. 8
   Lavageeluting first with hexane/EtOAc [4:1]

Mode opératoire

Sodium hydride (60% in mineral oil; 1.66 g [0.993 g NaH], 1.4 mmol, 1.10 equiv) was added to a solution of diethyl-2-cyano-4-fluorobenzyl phosphonate (10.2 g-equiv, 37.6 mmol, 1.0 equiv) in DMF (40 mL) over a period of 2 min. The reaction was stirred for 20 min at room temperature. 4-Fluorobenzaldehyde (4.67 g, 38 mmol, 1.0 equiv) was then added over a period of 2 min. After stirring for 18 h, H2O (200 mL) and satd. NaCl (50 mL) were added and the resulting mixture was extracted with EtOAc (2×100 mL). The combined organic layers were washed with 1N NaOH (1×100 mL) and H2O (2×100 mL), dried (anhyd. Na2SO4), and rotary evaporated (>100° C., heat gun). The crude, dark-red crystalline/oil (7.49 g, 82.7%) was chromatographed twice on silica gel (50×250 mm, dry pack), eluting first with hexane/EtOAc [4:1] and the second chromatography with [30:1] to provide a TLC-pure, yellow compound (2.1 g, 23.2%).

Source