Triphenylphosphine → 2-Chloro-4-(2-(trimethylsilyl)ethynyl)pyridine

Participants

Reaction Steps

2-Chloro-4-iodo-pyridine (10.0 g, 41.8 mmol) was dissolved in 200 mL dry THF and 17.5 mL triethyl amine. This mixture was evacuated and backfilled with argon several times to remove oxygen from the solution. Triphenylphosphine (329 mg, 1.25 mmol) and bis(triphenylphosphine)palladium(II) chloride (1.47 g, 2.09 mmol) were added and the reaction mixture was stirred at room temperature for 1 h. Copper(I) iodide (239 mg, 1.25 mmol) and trimethylsilylacetylen (6.28 g, 6.39 mmol) were added. The reaction mixture was stirred at room temperature overnight. The solvent was evaporated. The residue was taken up in 500 mL water and extracted three times with ethyl acetate (500 mL each). The combined organic extracts were dried with magnesium sulfate, filtered and evaporated. The crude product was purified by chromatography on silica gel (cyclohexane/ethyl acetate 80:20). The desired product was obtained as a light brown semi solid (10 g, >100%). This material was used without any further purification for the next step.

Provenance & Evidence