Oxidation, anthracene phenanthrene

The latter reagent also methylates certain heterocyclic compounds (e.g., quinoline) and certain fused aromatic compounds (e.g., anthracene, phenanthrene). The reactions with the sulfur carbanions are especially useful, since none of these substrates can be methylated by the Friedel-Crafts procedure (11-12). It has been reported that aromatic nitro compounds can also be alkylated, not only with methyl but with other alkyl and substituted alkyl groups as well, in ortho and para positions, by treatment with an alkyllithium compound (or, with lower yields, a Grignard reagent), followed by an oxidizing agent such as Bra or DDQ (P- 1511). 

In a different study, anthracene, phenanthrene, perylene 93 (Fig. 31), and 2,7-di-tert-butylpyrene underwent regioselective oxidative-substitution reactions with iodine(III) sulfonate reagents in dichloromethane to give the corresponding aryl sulfonate esters. The use of [hydroxy(tosyloxy)iodo]benzene, in conjunction with trimethylsilyl isothiocyanate, led to thiocyanation of the PAH nucleus. 

Both procaryotic and eukaryotic microorganisms have the enzymatic potential to oxidize aromatic hydrocarbons that range in size from a single ring (e.g., benzene, toluene and xylene) to polycyclic aromatics (PC As), such as naphthalane, anthracene, phenanthrene, benzo [a] pyrene and benz [a] anthracene (Table 4.4). However, the molecular mechanisms by which bacteria and higher microorganisms degrade aromatic compounds are fundamentally different. 

Chemically, creosote is a mixture of a great number of compounds, almost exclusively of cyclic structure. Individual compounds present in creosote in concentrations of 2-4% are acenaphthene, fluorene, diphenylene oxide, anthracene, and carbazole. Only one compound, phenanthrene, is present in a larger concentration (12-14%). For many years, chemists in many countries have tried tu isolate individual compounds and to find profitable uses for them. Most of these attempts have failed with exception of those involving anthracene. See also Anthracene. The principal use of creosote is for preservation of wood. Railroad lies, poles, fence posts, marine pilings, and lumber for outdoor use are impregnated with creosote in large cylindrical vessels. If properly treated, the life of the wood is greatly extended. Materials that are competitive with creosote for wood-preservation purposes include various petroleum oils, and pentachlorophenol. Pentachlorophenol is used in solutions of creosote or of petroleum oils. Blends of creosote with petroleum oils also are used for economic reasons. 

Naphthalene 1,2-oxide (136), a non-K-region epoxide, shows low thermal stability. Anthracene 1,2-oxide, on the other hand, is stable at ambient temperatures for several weeks. Preparation of (+ )-(lR,2S)-anthracene 1,2-oxide (137), using the above method, constitutes the first example of preparation of an optically pure arene oxide. However, the non-K-region oxides of phenanthrene, namely, its 1,2- and 3,4-oxides (47 and 48), obtained from chiral precursors, racemize fast.66 Perturbational molecular orbital calculations indicate that epoxide-oxepin valence tautomerism is possible. However, the oxepin could not be detected by NMR. 

Beltran et al. (1995) concluded that (1) the UV/ozone oxidation process can achieve high removal rates of fluorene, phenanthrene, and acenaph-thene, with total efficiencies being near 100% in some cases (2) neutral pH of 7 yields the highest removal rate of fluorene in solution and (3) the greater the bicarbonate concentration added to fluorene, the lower the removal efficiency becomes. When an excess of ozone is present in the reaction mixture, the degradation rate of anthracene, phenanthrene, and pyrene can be given as ... 

The direct oxidation of arenes to quinones is a reaction with a limited scope [41], Only substrates that form stable quinones give good yields. For example, oxidation of anthracene to stable 9,10-anthraquinone with chromic acid is practiced on industrial scale. Such oxidations are believed to proceed through a series of one-electron oxidation/solvolysis steps. Yields and selectivity may be improved by using a strong one-electron oxidant such as cerium ammonium nitrate (CAN), as in the oxidation of phenanthrene to phenanthrenequinones (Eq. 9) [42]. 

Boyd and co-workers interest in the properties of arene oxide metabolites has led them to undertake investigations into the synthesis and isomerization of such compounds (e.g., dibenz[ , ]anthracene 3,4-oxide 27, phenanthrene 3,4-oxide 28, triphenylene 1,2-oxide 29, and dibenz[ ,f]anthracene 1,2-oxide 30 (Figure 4)) <2001J(P1)1091>. 

EXPLOSION and FIRE CONCERNS combustible solid NFPA rating Health (not rated), Flammability 1, Reactivity 0 containers may explode in fire poisonous gases are produced in fire eomponents (sueh as anthracene, phenanthrene and acridine) are volatile contact with strong oxidizers may cause fires and explosions use water spray to keep fire-exposed containers cool dry chemical, carbon dioxide, or foam extinguishers may be used for firefighting purposes. 

The spiroisoxazoline 18, obtained from the nitrone 17 and dicyanoacetylene, rearranges to the pyiTolidinone 19 below 0 °C <97LA1691>. Irradiation of solvent-free mixtures of polycyclic aromatic hydrocarbons (anthracene, phenanthrene and pyrene) and the nitrile oxides mesitonitrile oxide or 3,5-dichloro-2,4,6-trimethylbenzonitrile oxide in a microwave oven at 650 W for 3.5-10 min. yields isoxazolines, e.t . 20, from phenanthrene <97H(45)1567>. 

The reactions of polynuclear aromatics can also be rationalized by simple models such as those shown for benzene in Figures 12.48 and 12.49. Two notable reactions are (i) the photodimerizations of anthracenes (equation 12.71) and (ii) the photoisomerization of frans-stilbene (99) to the cis isomer (100), followed by intramolecular photocycloaddition to a dihydrophenanthrene (101), which can then be oxidized to phenanthrene (102) ... 

Important Initiators and accelerators unsaturations, aromatic carbonyl compounds (deoxyanisoin, dibenzocycloheptadienone, flavone, 4-methoxybenzophe-none, 10-thioxanthone), hydrogen bound to tertiary carbon at branching points, aromatic amines, groups formed on oxidation (hydroperoxides, carbonyi, carboxyi, hydroxyi) substituted benzophenones, compiexes with ground-state oxygen, quinones (anthraquinone, 2-chioroanthraquinone, 2-tert-butyi-athraquinone, 1-methoxyanthraquinone, 2-ethyianthraquinone, 2-methyianthraquinone), transition metai compounds (Ni < Zn < Fe < Co), ferrocene derivatives, titanium dioxide (anatase), ferric stearate, poiynuciear aromatic compounds (anthracene, phenanthrene, pyrene, naphthaiene ... 

Fig. 4. Bacterial oxidation of phenanthrene and anthracene (RogofF and Wender, 1957, a, b).

In Europe, where an abundant supply of anthracene has usually been available, the preferred method for the manufacture of anthraquinone has been, and stiU is, the catalytic oxidation of anthracene. The main problem has been that of obtaining anthracene, C H q, practically free of such contaminants as carbazole and phenanthrene. Many processes have been developed for the purification of anthracene. Generally these foUow the scheme of taking the cmde anthracene oil, redistilling, and recrystaUizing it from a variety of solvents, such as pyridine (22). The purest anthracene may be obtained by azeotropic distillation with ethylene glycol (23). 

Os04 will add to C=C bonds but will only attack the most reactive aromatic bonds thus benzene is inert, but it will attack the 9,10 bond in phenanthrene and will convert anthracene to 1,2,3,4-tetrahydroxytetra-hydroanthracene. It can be used catalytically in the presence of oxidizing agents such as NaC103 or H2O2 [53],... 

Evans WC, HN Fernley, E Griffiths (1965) Oxidative metabolism of phenanthrene and anthracene by soil pseudomonads. The ring-fission mechanism. Biochem J 95 819-831. 

Hemoglobin is another heme-containing protein, which has been shown to be active towards PAH, oxidation in presence of peroxide [420], This protein was also modified via PEG and methyl esterification to obtain a more hydrophobic protein with altered activity and substrate specificity. The modified protein had four times the catalytic efficiency than that of the unmodified protein for pyrene oxidation. Several PAHs were also oxidized including acenaphthene, anthracene, azulene, benzo(a)pyrene, fluoranthene, fluorene, and phenanthrene however, no reaction was observed with chrysene and biphenyl. Modification of hemoglobin with p-nitrophenol and p-aminophenol has also been reported [425], The modification was reported to enhance the substrate affinity up to 30 times. Additionally, the solvent concentration at which the enzyme showed maximum activity was also higher. Both the effects were attributed to the increase in hydrophobicity of the active site. 

Methods for the synthesis of the biologically active dihydrodiol and diol epoxide metabolites of both carcinogenic and noncarcinogenic polycyclic aromatic hydrocarbons are reviewed. Four general synthetic routes to the trans-dihydrodiol precursors of the bay region anti and syn diol epoxide derivatives have been developed. Syntheses of the oxidized metabolites of the following hydrocarbons via these methods are described benzo(a)pyrene, benz(a)anthracene, benzo-(e)pyrene, dibenz(a,h)anthracene, triphenylene, phen-anthrene, anthracene, chrysene, benzo(c)phenanthrene, dibenzo(a,i)pyrene, dibenzo(a,h)pyrene, 7-methyl-benz(a)anthracene, 7,12-dimethylbenz(a)anthracene, 3-methylcholanthrene, 5-methylchrysene, fluoranthene, benzo(b)fluoranthene, benzo(j)fluoranthene, benzo(k)-fluoranthene, and dibenzo(a,e)fluoranthene. 

Nucleophilic Trapping of Radical Cations. To investigate some of the properties of Mh radical cations these intermediates have been generated in two one-electron oxidant systems. The first contains iodine as oxidant and pyridine as nucleophile and solvent (8-10), while the second contains Mn(0Ac) in acetic acid (10,11). Studies with a number of PAH indicate that the formation of pyridinium-PAH or acetoxy-PAH by one-electron oxidation with Mn(0Ac)3 or iodine, respectively, is related to the ionization potential (IP) of the PAH. For PAH with relatively high IP, such as phenanthrene, chrysene, 5-methyl chrysene and dibenz[a,h]anthracene, no reaction occurs with these two oxidant systems. Another important factor influencing the specific reactivity of PAH radical cations with nucleophiles is localization of the positive charge at one or a few carbon atoms in the radical cation. 

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