Pyrrol yields an analogous series: pyrazole, imidazole or glyoxaline, azimide or osotriazole, triazole and tetrazole: CH=N N=CH N=N CH=CH' CH =CH' CH =CH' Pyrazole.
In a similar manner, formic acid and dicyanophenylhydrazine yields a phenyl-triazole carboxylic acid, in which the phenyl group may be nitrated, the nitro group reduced to the amino group, and the product oxidized to a triazole carboxylic acid, which, by elimination of carbon dioxide, yields the free triazole: HO 2 C C=N H02C C =N, NPh-> N :CH N :CH They also result when the acidylthiosemicarbazides are strongly heated, the mercapto-triazoles so formed being converted into triazoles on oxidation with hydrogen peroxide (M.
N=CHN=N N = CH NH N = CH?NH Triazole.
It behaves as a strong acid and on treatment with phosphorus pentachloride at high temperatures gives triazole.
NPh PhN N Triphenyl-endoiminodihydro triazole.