Azimine. VII . Herstellung durch Oxydation von Triazanen

Azimines. VII Teil VI, s. [1]. . Preparation by Oxidation of Triazanes A novel method for the preparation of certain azimines 4 by oxidation of 1,2,3‐trisubstituted triazanes 3 is described. Treatment of 3‐aryl‐triazane‐1,2‐diesters 3a‐3c with lead tetraacetate afforded the 3‐aryl‐azimine‐1,2‐diesters 4a‐4c . The precursor triazanes 3a‐3c were prepared by addition of p ‐substituted anilines to diisopropyl diazene‐1,2‐dicarboxylate 1b . A comparison of the spectral properties of the azimines 4 with those of the correspondingly substituted triazanes 3 reveals the unsaturated and dipolar nature of the azimines 4 .