The synthetic importance of 2-hydrazinobenzimidazoles
is well known: they underlie the
preparation of new heterocyclic systems [1–3],
formazans [4], coordination compounds [5]. The
synthetic opportunities of N-amino-benzimidazoles are
no less versatile [6, 7]. We describe in this report 1-
amino-2-hydrazinobenzimidazole I with both functionnal
groups participating in condensations and the features
of its reactions with aldehydes, 2,4-pentanedione,
and α-ketoacids.
The main method of the preparation of 2-