Nucleophilic Attack of Azide at Electrophilic Azides: Formation of N6 Units in Hexazene and Aminopentazole Derivatives.

Abstract

With the help of selective 15N labeling experiments, it has been confirmed that nucleophilic attack of azide at iminium‐activated organic azides leads to short‐lived hexazene intermediates. Such species do not only tend to a cleavage reaction with formation of N‐azido compounds, but also undergo ring closure to generate unprecedented amidino‐functionalized pentazoles. Thus, treatment of the parent Vilsmeier reagent with two equivalents of sodium azide creates an aminopentazole derivative as the main product, which is easily characterized by NMR spectroscopy.