Reaktion #1277

Reaktionsgleichung

3,4-difluorobromobenzene

water

4-(4-propylcyclohexyl)-phenyltrimethoxysilane

TBAF

→

white crystals

Ausbeute 94.5%

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

Ausbeute 94.5%

Lösungsmittel

toluene

toluene

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter the solvent was removed under reduced pressure
2. 2
   TemperaturThe resulting mixture was refluxed for 3 hours
3. 3
   TemperaturAfter cooling, to the reaction mixture
4. 4
   SonstigeThe organic layer was separated
5. 5
   Extraktionthe aqueous layer was extracted with toluene three times
6. 6
   TrocknenThe combined organic layer was dried over magnesium sulfate
7. 7
   SonstigeAfter the magnesium sulfate was removed by filtration
8. 8
   Sonstigethe filtrate was evaporated under reduced pressure
9. 9
   SonstigeThe residue was purified by silica gel column chromatography (heptane)

Vorschrift

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.

Quelle