Oxidation, anthracene naphthalene

Comparison of the reactivities of benzene oxides, naphthalene oxides, phenanthrene oxides, and arene oxides derived from benzo [a] pyrene and 7,12-dimethylbenz[a] anthracene with hepatic glutathione S-epoxide transferase showed that benzene oxides without electron-withdrawing groups are poor substrates as also are polycyclic arene oxides. Only naphthalene oxide was a good substrate. 

Addition of cerium salts accelerates the electrolytic oxidation of anthracene, naphthalene, and phenanthrene, which yield the corresponding quinones. The hydrocarbons may be in solution or in the form of a finely divided suspension. Anthracene, for example, is oxidised to Anthraqtjinone in 20 per cent, sulphuric acid anode current density is about 5 amps, per dm.2, and by the addition of 2 per cent, of cerium sulphate the current efficiency 8 is stated to reach nearly 100 per cent. 

Introduction. The quinones are intermediate products in the oxidation of the aromatic nucleus. They may be prepared in some cases by the direct oxidation of aromatic hydrocarbons. For example, anthracene, naphthalene, and phenanthrene are oxidized to the corresponding quinones by chromic acid mixtures. Quinones are prepared more conveniently by oxidation of primary aromatic amines, particularly the p-substituted amines. p-Benzoquinone is obtained by the oxidation of aniline, p-toluidine, sulfanilic acid, p-aminophenol, and other similar compounds. Similarly the a-naph-thoquinone is obtained by oxidation of 1,4-aminonaphthol, and /9-naphthoquinone by the oxidation of 1,2-aminonaphthol. In the laboratory, although it is possible to prepare p-benzoquinone by the oxidation of aniline with acid-dichromate mixture, the method is tedious and the yield poor. Since hydroquinone is used extensively as a photographic developer and is made industrially, it is more convenient to prepare quinone by its oxidation. 

Peracid oxidation of naphthalene leads to a/m -I,2 3,4-naphthaiene dioxide (2, 15-207o yield).A similar oxidation of 2-methylnaphthalene gives both syn- and an//-dioxides. Oxidation of anthracene results mainly in the quinone, but 9,10-diphenylanthracene can be oxidized to a dioxide of still uncertain structure. 

Polycyclic aromatic hydrocarbons (perylene, tetracene, anthracene, naphthalene), their alkyl- and aryl-substituted derivatives and compounds of the benzene series having strong electron-releasing substituents (p-dialkoxybenzenes, p-bisdialkyl-aminobenzenes etc.) are oxidized to yield radical cations upon action of Lewis-type acids(SbCl5 AICI3 AICI3 combined with RNO ... 

Industrial gas-phase oxidation of anthracene is performed in a way comparable to the oxidation of naphthalene to PA or naphthoquinone. 

Anthraquinone itself is traditionally available from the anthracene of coal tar by oxidation, often with chromic acid or nitric acid a more modern alternative method is that of air oxidation using vanadium(V) oxide as catalyst. Anthraquinone is also produced in the reaction of benzene with benzene-1,2-dicarboxylic anhydride (6.4 phthalic anhydride) using a Lewis acid catalyst, typically aluminium chloride. This Friedel-Crafts acylation gives o-benzoylbenzoic acid (6.5) which undergoes cyclodehydration when heated in concentrated sulphuric acid (Scheme 6.2). Phthalic anhydride is readily available from naphthalene or from 1,2-dimethylbenzene (o-xylene) by catalytic air oxidation. 

We then focused our attention to the cationic species generated from a series of condensed aromatics fully annelated with BCO units. Newly synthesized naphthalene 12 (17), anthracene 13 (18), biphenylene 14 (19), and fluorene 15 (20) all underwent smooth one-electron oxidation by the use of 1.5... 

Use has been made of the C-N cleavage in the conversion of the bicyclic tertiary amines, derived from the 4tc + 2tc cycloaddition of pyrroles and isoindoles with benzynes, into aromatic systems, e.g. naphthalen-l,4-imines and anthracen-9,10-imines yield naphthalenes and anthracenes with the extrusion of the nitrogen bridge [24] in yields which are higher than those obtained by standard oxidation procedures. 

This section is dedicated to arene oxides of bicyclic and tricyclic arenes (e.g., naphthalene, anthracene, and phenanthrene oxides), whereas higher arenes and particularly benzo[a]pyrene (one of the most toxic and intensively investigated PAHs) are examined in Sect. 10.4.4. 

Fig. 10.9. Stereoselective formation of the 1,2-dihydrodiols of naphthalene and anthracene from their precursor 1,2-oxides, 10.2 and 10.24, respectively (modified from [86])... 

P. J. van Bladeren, J. M. Sayer, D. E. Ryan, P. E. Thomas, W. Levin, D. M. Jerina, Differential Stereoselectivity of Cytochrome P450b and P450c in the Formation of Naphthalene and Anthracene 1,2-Oxides. The Role of Epoxide Hydrolase in Determining the Enantiomer Composition of the 1,2-Dihydrodiols Formed ,. /. Biol. Chem. 1985, 260, 10226- 10235. 

A third important reaction of aromatic radical-cations is carbon-carbon bond formation with a further aromatic substrate. This reaction is limited to the oxidation in acetonitrile of substrates with electrondonating substituents. Radical-cations from benzene, naphthalene and anthracene form a-complexes but do not form a a-bonded reaction intermediate. Tlie dimerization reaction has been investigated both by pulse-radiolysis [22] in water and by electrochemical methods [27] in acetoni-... 

Benzene, naphthalene and anthracene afford quinones by oxidation in aqueous based media and these processes are technically important. Electrochemical oxida-... 

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