Synthesis of o-azobispyrazole derivatives

Azobispyrazoles were obtained by diazo coupling of diazotized o-aminoazopyrazoles. The o-azobispyrazole obtained from 3-methyl-1-phenyl-5-pyrazolone exists in the o-azohydrazone form, whereas the o-azobispyrazole obtained from 5-amino-3-methylpyrazole exists in the o-azobis form. A 3-azo derivative of naphtho[2,1-e]-pyrazolo[5,1-c]triazine is formed from 2-naphthol. The structures of the compounds obtained were confirmed by IR, UV, PMR, and mass spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 382–387, March, 1978.