[Abstract] Reaction of Reissert-Henze salt with silver acetylide gave the pyridine ethynylated selectively at 2-position. 2-(Phenylethynyl)pyridines substituted 3-position with a carbonyl or masked carbonyl group were converted to various bicyclic pyridine derivatives by intramolecular cyclization. 3-Cyano-2-(phenylethynyl)pyridine was cyclized intramolecularly under acidic conditions to give the naphthyridine and pyranopyridine derivatives. 2-(Phenylethynyl)pyridine reacted with dimethyl acetylenedicarboxylate in the presence of a proton source to give indolizines having methoxycarbonyl groups at the 2- or 2,3-positions
