Open chain nitrogen compounds. Part XI. 3,7-Bis(arylazo)-1,3,5,7-tetraazabicyclo[3,3,1]nonanes: the reaction of diazonium ions with ammonia–formaldehyde mixtures

Abstract

Reaction of a series of diazonium salts with either hexamine or an aqueous mixture of ammonia–formaldehyde affords 3,7-bis(arylazo)-1,3,5,7-tetraazabicyclo[3,3,1]nonanes; several new examples of this novel class of bicycloheterocycle have been prepared and characterized. Analysis of the low-temperature nmr spectra of one compound in this series shows that the bicyclic system prefers the chair–chair conformation. The bis(arylazo)tetraazabicyclononanes, which are surprisingly stable in aqueous buffer compared to analogous triazenes of open-chain structure, do undergo slow decomposition at slightly acidic pH in an acetone–buffer mixture. The apparent product of this decomposition is the arylamine, which is observed as the Mannich condensation product, ArNH•CH2CH2COCH3.