Hexane → 3-Chloro-5-[2-(trimethylsilyl)ethynyl]pyridine

Participants

Reaction Steps

5-Chloro-3-pyridinyl trifluoromethanesulfonate (4.0 g, 15 mmol) and CuI (580 mg, 3.0 mmol) were combined in DMFE (100 mL) and argon gas was bubbled through the suspension for several minutes to deoxygenate the mixture. Triethylamine (10.6 mL, 76.5 mmol), and PdCl2(PPh3)2 (1.1 g, 1.5 mmol) were added, then trimethylsilyl-acetylene (3.3 ml, 23 mmol) was added dropwise. The reaction mixture was stirred at ambient temperature for 1 h at which time GC/MS analysis indicated that the reaction was complete. The mixture was filtered through Celite™, and the filter pad was washed thoroughly with ethyl acetate. The combined filtrates were concentrated in vacuo and the residue was dissolved in ethyl acetate (300 mL), washed with water (300 mL), brine (300 mL), dried over Na2SO4 filtered, and concentrated in vacuo. The residue was purified by column chromatography eluting with hexane then 99:1 hexane:ethyl acetate to afford 3-chloro-5-[(trimethylsilyl)ethynyl]pyridine (2.8 g, 87% yield) as a brown solid. 1H NMR (CDCl3, 300 MHz) δ 8.51 (s, 1H), 8.44 (s, 1H), 7.70 (s, 1H), 0.22 (s, 9H). MS (EI ionization) 209 (M+).

Provenance & Evidence