2-Bromopyridine → HCID 22618301, compound

Participants

Reaction Steps

A suspension of 5-chloro-2-(3,5-di-t-butyl-4-hydroxy-benzyl)-7-ethynyl-benzoxazole (2.38 g, 6.0 mmol), 2-bromo-pyridine (0.66 ml, 98%, 6.6 mmol), bis(triphenylphosphine)palladium(II) dichloride (21.1 mg, 30 μmol) and copper (I) iodide (1.2 mg, 6 μmol) in triethylamine (12 ml) was heated at 90EC, under argon, for 1.5 hours. The triethylamine was removed in-vacuo and the residue dissolved in ether (100 ml). The organics were washed with water (50 ml), 1 N HCl (100 ml) and saturated aqueous sodium hydrogen carbonate (100 ml), dried (Na2SO4) and evaporated in-vacuo to give 2.96 g (104.2%) of crude pyridyl ethynyl benzoxazole. The crude benzoxazole was purified by column chromatography (SiO2; dichloromethane), and the product crystallized from methanol and suspended in hot water. The resulting crystals were collected, washed, and dried to give 1.49 g (52.5%) of the title compound (mp 138-9EC).

Provenance & Evidence