Triphenylphosphine → 4-[2-(Trimethylsilyl)ethynyl]pyridine-2-carbonitrile

Participants

Reaction Steps

4-Bromo-2-pyridinecarbonitrile [Cesko-Slovenska Farmacie 25(5),181(1976)] (0.73 g, 4.0 mmol) was dissolved in 18 mL dry THF. This mixture was evacuated and backfilled with argon several times to remove oxygen from the solution. Triphenylphosphine (31 mg, 0.12 mmol) and bis(triphenylphosphine)palladium(II) chloride (141 mg, 0.20 mmol) were added and the reaction mixture was stirred at room temperature for 1 h. Copper(I) iodide (23 mg, 0.12 mmol) and trimethylsilyl-acetylene (590 mg, 6.0 mmol) were added. The reaction mixture was stirred at room temperature for 3 days. The solvent was evaporated. The residue was taken up in 100 mL water and extracted three times with 100 ml of ethyl acetate. The combined organic extracts were dried with magnesium sulfate, filtered and evaporated. The crude product was purified by flash chromatography on silica gel (heptane/methylene chloride 1:2). The desired product was obtained as a yellow oil (329 mg, 41%), MS: m/e=201.3 (M+H+).

Provenance & Evidence