Triphenylphosphine → 2-(5-Bromopent-1-ynyl)pyridine

Participants

Reaction Conditions

Reaction Steps

Br2 (1.11 mL, 21.4 mmol) was added to a solution of triphenylphosphine (8.30 g, 30.7 mmol) in DCM (40 mL) at −5° C. A solution of 5-pyridin-2-yl-pent-4-yn-1-ol (3.00-18.6 mmol) in DCM (10 mL) was added dropwise to the reaction mixture in order to maintain a temperature lower than 5° C. The reaction mixture was stirred for 5 hours at −10° C. and was quenched with a saturated solution of NaHCO3. The aqueous phase was extracted with DCM. The resulting organic phase was washed with brine dried over MgSO4, filtered and evaporated. The crude residue was purified by flash chromatography (DCM/MeOH 99.5:0.5) to yield 2-(5-bromo-pent-1-ynyl)-pyridine (1.20 g, 5.35 mmol, 29%) with a purity of 50%.

Provenance & Evidence