Réaction #1277

Équation de réaction

3,4-difluorobromobenzene

water

4-(4-propylcyclohexyl)-phenyltrimethoxysilane

TBAF

→

white crystals

Rendement 94.5%

4-(4-propylcyclohexyl)-3',4'-difluorobiphenyl

Rendement 94.5%

Solvants

toluene

toluene

toluene

Conditions de réaction

Traitement

1. 1
   AutreAfter the solvent was removed under reduced pressure
2. 2
   TempératureThe resulting mixture was refluxed for 3 hours
3. 3
   TempératureAfter cooling, to the reaction mixture
4. 4
   AutreThe organic layer was separated
5. 5
   Extractionthe aqueous layer was extracted with toluene three times
6. 6
   SéchageThe combined organic layer was dried over magnesium sulfate
7. 7
   AutreAfter the magnesium sulfate was removed by filtration
8. 8
   Autrethe filtrate was evaporated under reduced pressure
9. 9
   AutreThe residue was purified by silica gel column chromatography (heptane)

Mode opératoire

To 0.645 g (2 mmol) of 4-(4-propylcyclohexyl)-phenyltrimethoxysilane (Ih) was added 2.1 ml of TBAF (2.1 mmol, 1M in THF) under nitrogen, and the mixture was stirred at room temperature for 30 minutes. After the solvent was removed under reduced pressure, a solution of 3,4-difluorobromobenzene (0.463 g, 2.4 mmol) in toluene (1 ml) was added, followed by the addition of a suspension of tetrakis(triphenylphosphine)palladium(0) (0.116 g, 0.1 mmol) in toluene (3 ml). The resulting mixture was refluxed for 3 hours. After cooling, to the reaction mixture were added water and toluene. The organic layer was separated and the aqueous layer was extracted with toluene three times. The combined organic layer was dried over magnesium sulfate. After the magnesium sulfate was removed by filtration, the filtrate was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (heptane) to obtain 0.594 g (40%) of white crystals.

Source