Triazines and related products. Part 21. Cyclisation of 3-amino-5-hydrazinopyrazole and 3-amino-5-hydrazino-1,2,4-triazole to azolo[5,1-c][1,2,4]triazines

Abstract

Interaction of malononitrile with two equivalents of hydrazine hydrate affords 3-amino-5-hydrazinopyrazole in high yield. The pyrazole reacts with ethyl pyruvate, diacetyl, and benzil to yield derivatives of 2-aminopyrazolo[5,1-c][1,2,4]triazine: amino-1,2,4-triazolo[5,1-c][1,2,4]triazines are similarly formed from 3-amino-5-hydrazino-1,2,4-triazole.