What is "pyridyne"

Pyridyne in chemistry is the pyridine analogue of benzyne. This reactive intermediate is of some importance to scientific research. Pyridynes are the class of compounds sharing the pyridyne building motive. Two isomers exist, the 2,3-pyridine (2,3-didehydropyridine) and the 3,4-pyridyne (3,4-didehydropyridine). The reaction of 3-bromo-4-chloropyridine with furan and lithium amalgam gives 1,4-epoxy-dihydroquinoline through the 2,3-pyridyne intermediate. The reaction of 4-bromopyridine with sodium in liquid ammonia gives both 3-aminopyridine and 4-aminopyridine through the 3,4-pyridyne intermediate and an E1cB-elimination reaction.