Reaction of N-Aminopyridinium Derivatives. VI. Properties of s-Triazolo [1, 5-α] pyridine Ring.

s-Triazolo [1, 5-α] pyridine ring was quite stable and showed properties similar to those of aromatic compounds. Nitration of 2-methyl-s-triazolo [1, 5-α] pyridine (IV) with potassium nitrate and sulfuric acid gave two mononitro compounds (V) and (VI). Catalytic reduction of V and VI gave the corresponding amino derivatives (VII) and (VIII) which were further converted to the corresponding bromo derivatives (IX) and (X) by the Sandmeyer reaction. But this ring was quite unstable against oxidation and fission of the pyridine ring occurred to give s-triazole derivatives.