Mutual effect of the N-amino group and the heteroring in N-aminobenzazoles
The basicity constants, NH acidities, and anode oxidation potentials of N-amino derivatives of a number of heteroaromatic systems, viz., indole, benzimidazole, indazole, and 1,3-dimethylxanthine, were measured for the first time. The results obtained provide evidence for the inductive character of the interaction of the N-amino group and the benzazole ring vis-á-vis the almost complete absence of π interaction between them; the heteroring has a very strong electron-acceptor effect on the properties of the amino group, while the amino group changes the properties of the heteroring to only a small extent.