Benzyne generated from fluoride-induced reaction of o-trimethylsilylaryl triflates was found to be copolymerized with pyridine to give novel alternating copolymers bearing o-phenylene and 2,3-dihydropyridine units in the main chain. The unique polymer structures were confirmed from the elemental analyses, MALDI-TOF-MS, and IR, although H-1 NMR spectra of the polymers did not exhibit the signals of protons on the pyridine-derived rings. The copolymers obtained as HCl adducts of pyridine-derived rings can be converted to neutral forms via treatment with NaOH aqueous solution, where nucleophilic attack of hydroxide anion to the pyridine-derived rings resulted in the incorporation of hydroxy and imine groups on the cyclic structure. The mechanism of the copolymerization and the transformation with the alkaline treatment thereafter was proposed. This is the first example that benzyne generated from o-trimethylsilylaryl triflates can be used as a monomer for polymerization.