A convenient synthesis of five-membered heteroaryl―substituted pyridines

Five-membered heteroarylpyridines (3) or (4) such as furylpyridines, thienylpyridines, imidazolylpyridines and pyrrolylpyridines were obtained regioselectively in appreciable yields (40-67%) by reaction of heteroaryllithium salts with N-ethoxycarbonylpyridinium chloride (1) followed by oxygen oxidation