Reacción #1277

Ecuación de reacción

3,4-difluorobromobenzene

water

4-(4-propylcyclohexyl)-phenyltrimethoxysilane

TBAF

→

white crystals

Rendimiento 94.5%

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

Rendimiento 94.5%

Disolventes

toluene

toluene

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroAfter the solvent was removed under reduced pressure
2. 2
   TemperaturaThe resulting mixture was refluxed for 3 hours
3. 3
   TemperaturaAfter cooling, to the reaction mixture
4. 4
   OtroThe organic layer was separated
5. 5
   Extracciónthe aqueous layer was extracted with toluene three times
6. 6
   SecadoThe combined organic layer was dried over magnesium sulfate
7. 7
   OtroAfter the magnesium sulfate was removed by filtration
8. 8
   Otrothe filtrate was evaporated under reduced pressure
9. 9
   OtroThe residue was purified by silica gel column chromatography (heptane)

Procedimiento

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.

Fuente