Hydrochloric Acid → 4-[(Trimethylsilyl)ethynyl]pyridine

Participants

Reaction Steps

A flask was charged with 4-bromopyridine.HCl (2.46 g, 12.65 mmol) and triethylamine (40 mL) and sparged with nitrogen for 15 min. To this was added ethynyltrimethylsilane (1.967 mL, 13.92 mmol) and purged 15 min longer. To this was added copper(I) iodide (0.120 g, 0.633 mmol), and Pd(PPh3)2Cl2 (0.444 g, 0.633 mmol). The reaction was stirred at room temperature for 72 h. The reaction was warmed to 50° C. and held at that temperature for 24 h. The reaction was diluted with ethyl acetate (60 mL) and poured into water. The black heterogeneous emulsion was filtered through a plug of celite and the layers separated. The organics were washed with brine, dried over magnesium sulfate, and concentrated. Column chromatography (5%-->25% EtOAc/Hex) gave 667 mg (30%) as a dark oil. 1H-NMR (CDCl3, 500 MHz) δ 8.58 (d, J=6.1, 2H), 7.33 (d, J=6.1, 2H), 0.29 (s, 9H). 13C-NMR (CDCl3, 126 MHz) δ 149.8, 131.3, 125.9, 102.1, 100.1, −0.2. Mass spec.: 176.14 (MH)+.

Provenance & Evidence