Reaction #2139944

Reaction equation

4-bromo-2-fluoro-1-iodobenzene

1-pentyne

water

ether

→

4-bromo-2-fluoro-1-pent-1-ynylbenzene

Solvents

THF

triethylamine

Conditions

Workup

1. 1
   workup.STIRRINGthe mixture was stirred for a further 5 minutes
2. 2
   FiltrationThe reaction mixture was filtered through Celite® with suction
3. 3
   Otherthe phases were separated
4. 4
   ExtractionThe aqueous phase was extracted twice with MTB ether
5. 5
   Washthe combined organic phases were washed three times with water
6. 6
   Dryingdried over sodium sulfate
7. 7
   Otherevaporated under reduced pressure
8. 8
   FiltrationThe crude product was filtered through silica gel with n-heptane

Procedure

190 g (0.600 mol) of 4-bromo-2-fluoro-1-iodobenzene and 65.3 ml of 1-pentyne were dissolved in a mixture of 900 ml of THF and 1.2 l of triethylamine and cooled to 10° C., and 1.14 g (6 mmol) of copper(I) iodide and 8.42 g (12 mmol) of bis(triphenylphosphine)palladium(II) chloride were added. The batch was stirred overnight at room temperature, water and MTB ether were subsequently added, and the mixture was stirred for a further 5 minutes. The reaction mixture was filtered through Celite® with suction, and the phases were separated. The aqueous phase was extracted twice with MTB ether, and the combined organic phases were washed three times with water, dried over sodium sulfate and evaporated under reduced pressure. The crude product was filtered through silica gel with n-heptane, giving 129 g of 4-bromo-2-fluoro-1-pent-1-ynylbenzene as a yellow liquid. Hydrogenation on palladium/activated carbon (10%) in THF gave 131 g (100%) of 4-bromo-2-fluoro-1-pentylbenzene as a yellow liquid.

Source