2-Bromothiazole → HCID 22618309, 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-bromothiazole (1.13 ml, 95%, 12 mmol), bistriphenylphosphine)palladium(II) dichloride (21.1 mg, 30 μmol), and copper (I) iodide (1.2 mg, 6 μmol) in triethylamine (12 ml) was heated at 90 EC, under argon, for 3 hours. The triethylamine was removed in-vacuo and the residue dissolved in ether (70 ml) and water (30 ml). The organics were washed with 1 N HCl (30 ml) and saturated sodium hydrogen carbonate (30 ml), dried (Na2SO4) and evaporated--to give 2.86 g (100%) of crude thiazolylethynylbenzoxazole, which was purified by flash chromatography (SiO2 ; dichloromethane). The product was crystallized and recrystallized from methanol to give 1.43 g (50.4%) of the title compound (mp 137-41 EC).

Provenance & Evidence