Studies on the reactivity of azoxybenzenes. Part 12. αβ-Interconversion of para-monosubstituted azoxybenzenes in the Wallach rearrangement
Abstract
Under the reaction conditions for the Wallach rearrangement, 4-methyl-ONN-(1α), 4-methyl-NNO-(1β), 4-nitro-ONN-(2α), and 4-nitro-NNO-azoxybenzene (2β) were found to undergo αβ-interconversion, while 4-bromo-ONN-(3α) and 4-bromo-NNO-azoxybenzene (3β) do not. The αβ-interconversion occurs with both mono- and di-protonated forms of the azoxybenzenes.