Synthesis of Pyrazine-Thiazole Biheteroaryl Compounds through Base-Promoted Oxidative Cross-Dehydrogenative Coupling Reactions

An efficient and concise one-pot protocol for the oxidative cross-dehydrogenative coupling reaction of pyrazine N-oxides and 1,3-azole derivatives has been developed. Commercially available and inexpensive 1,3-azoles were used as the coupling partners. Various biheteroaryl compounds were obtained in up to 67% yields. This methodology provides a convinent way to construct the pyrazine-thiazole biheteroaryl moieties. Thermogravimetric analysis indicated that the fracture temperature of one of the biheteroaryl compounds was about 237 degrees C.