1,10-Phenanthroline → 2-(5-Bromo-2-pyridinyl)benzoxazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-bromoaniline (3.90 g, 22.7 mmol), 5-bromopyridine-2-carbonyl chloride (5.00 g, 22.7 mmol), Cs2CO3 (14.78 g, 45.36 mmol), 1,10-phenanthroline (0.409 g, 2.27 mmol), CuI (0.216 g, 1.13 mmol) and anhydrous 1,4-dioxane (40 mL) was degassed with argon for about 40 min while stirring. The stirring reaction mixture was then maintained under argon at about 120° C. for about 40 h. Upon completion, the reaction was cooled to RT and poured over CH2Cl2 (300 mL). The organics were then washed with sat. NaHCO3, H2O and brine, dried over MgSO4, filter and concentrated in vacuo. Purification of the crude product via flash chromatography (SiO2, 4:1 dichloromethane-hexanes) and subsequent recrystallization from hexanes afforded compound 11 (1.86 g, 30% yield) as colorless fibers.

Provenance & Evidence