At room temperature, 2-chloro-5-(furan-2-yl)pyrazine (N. Sato, J. Heterocyclic Chem., 19, 407(1982)) (1.00 g) and (pyridin-4-yl)boronic acid (1.09 g) were suspended in a mixed solvent of dimethoxyethane (50 ml) and methanol (50 ml), followed by the successive addition of tetrakis(triphenylphosphine)palladium (O) (640 mg) and cesium fluoride (5.55 g). The resulting mixture was heated under reflux for 16 hours. After cooling, the reaction mixture was concentrated. Dichloromethane and water were added to the concentrate to separate the organic layer. The organic layer was dried over anhydrous sodium sulfate, treated with activated carbon and filtered through Celite. After the filtrate was concentrated to about 5 ml, petroleum ether (50 ml) was added to the concentrate. Yellow crystalline powder thus precipitated was collected by filtration and dried, whereby the title compound (716 mg, 58%) was obtained.
