Aryliminodimagnesium Reagents. XVI. Formation of o-Hydroxyazoarenes by Condensation with o-Hydroxynitroarenes. Favorable Role of o-Hydroxyl Group in the Reaction

Article abstract of DOI:10.1246/bcsj.62.1621

Hydroxy(HO)-azoxy and -azoarenes were formed by condensation of ArN(MgBr)2 with o-, m-, and p-HO-nitrobenzenes; nuclear substitution took place as a minor or a major pathway. o-HO-azobenzene was obtained in sufficiently high yield.Relative yields of the products varied according to the position of HO group and reaction conditions.The yield variation was explained by the effects of relative efficiency of single electron transfer, ?-complexation, and cooperation of reagent molecules.