Dichloromethane → 2-Bromo-5-(4-[1,2,3]triazol-1-yl-but-1-ynyl)-pyrazine

Participants

Reaction Steps

2-Bromo-5-iodo-pyrazine (13.69 g, 48.0 mmol), 1-but-3-ynyl-1H-[1,2,3]triazole (7.01 g, 57.9 mmol) and triethyl amine (NEt3) (94 ml) are dissolved in DMF (188 ml) and copper iodide (CuI) (0.984 g, 5.17 mmol) is added under stirring. After passing a stream of argon through the mixture for 10 min tetrakis(triphenylphosphine)palladium(0) (2.844 g, 2.46 mmol) is added and stirring is continued for 5 h at r.t. Dichloromethane (300 ml) is added; the mixture is washed with 0.5N hydrochloric acid (HCl) and brine, dried over Na2SO4 and concentrated in vacuo. The crude product is purified by flash column chromatography (ethyl acetate/hexanes 7:3) yielding 2-bromo-5-(4-[1,2,3]triazol-1-yl-but-1-ynyl)-pyrazine as a colorless solid. Yield 9.99 g (75%).

Provenance & Evidence