Azoxybenzene is

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

with the formula C₆H₅N(O)NC₆H₅. It is a yellow, low-melting solid. The molecule has a planar C₂N₂O core. The N-N and N-O bond lengths are nearly the same at 1.23 Å.

Preparation

It can be prepared by partial reduction of

nitrobenzene Nitrobenzene is an organic compound with the chemical formula C6H5 NO2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor t ...

. This reaction is proposed to proceed via the intermediacy of

phenylhydroxylamine Phenylhydroxylamine is the organic compound with the formula C6H5NHOH. It is an intermediate in the redox-related pair C6H5NH2 and C6H5NO. Phenylhydroxylamine should not be confused with its isomer α-phenylhydroxylamine or ''O''-phenylhydroxyl ...

and

nitrosobenzene Nitrosobenzene is the organic compound with the formula C6H5NO. It is one of the prototypical organic nitroso compounds. Characteristic of its functional group, it is a dark green species that exists in equilibrium with its pale yellow dimer. Bot ...

: :PhNHOH + PhNO → PhN(O)NPh + H₂O Another option is the oxidation of

aniline Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine In organic chemistry, an aromatic amine is an organic compound consisting of an aroma ...

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

, in acetonitrile at 50 ºC. In this reaction, the pH should be kept around 8, to activate the hydrogen peroxide and avoid too much oxygen evolution at the same time. First, the acetonitrile is oxidized, forming an imine hydroperoxide. Then, this intermediate oxidizes the aniline to azoxybenzene. {{cite journal, title=Reactions of Hydrogen Peroxide. VII. Alkali-Catalyzed Epoxidation and Oxidation Using a Nitrile as Co-reactant, authors=George B. Payne, Philip H. Deming, Paul H. Williams, journal= The Journal of Organic Chemistry, year=1961, volume=26, issue=3 , page=659-663, doi=10.1021/jo01062a004 :CH₃CN + H₂O₂ → H₃C(OOH)=NH:2 PhNH₂ + 3 H₃C(OOH)=NH→ PhN(O)NPh + 3 CH₃C(O)NH₂ + 2 H₂O :PhNO2 + Na₃AsO₃/NaOH→ Ph−N⁺O⁻=N-Ph

References

Phenyl compounds Azo compounds