bearing an ortho-(tert-butyl)-NNO-azoxy group. BTOs bearing electron-releasing substituents were obtained by nucleophilicdisplacements of bromine in 4b−d. The formation of the BTO cyclic system involves the intermediate 2-(tert-butyl)-1,2,3,4-benzotetrazinium 4-oxides, which arise from an N,N-[1,2]-shift of the tert-butyl group. Decomposition of BTOs involves opening of the tetrazine ring to afford ortho-azidonitroso