Catalyst 4-anthracene

Some polynuclear aromatics, such as anthracene, can be brominated without a catalyst (23)... 

Equimolar amounts of anthracene,/ -benzoquinone, and aluminum chloride give the faintly yellow adduct in 15 minutes. The product is unstable to heat turning yellow at 207°, turning red at 210°, and slowly charring. When 2 molar equivalents of anthracene are used, the bis adduct is obtained, mp 230°, unobtainable in the absence of the catalyst. 

A solution of 10 g of 9 10-dihydro-9 10-ethano-(1 2)-anthracene-(9)aldehyde (made from anthracene and acrolein) and 10 g of monomethylamine in 100 cc of ethanol is heated at 80°C for 4 hours in an autoclave. The reaction mixture is then evaporated to dryness under reduced pressure to leave a crystalline residue which is dissolved in 150 cc of ethanol and, after the addition of 2 g of Raney nickel, hydrogenated at 40°C under atmospheric pressure. When the absorption of hydrogen has subsided, the catalyst is filtered off and the filtrate evaporated under reduced pressure. An oil remains which is covered with 100 cc of 2N hydrochloric acid. The 9-methylamino-methyI-9 10-dihydro-9 10-ethano-(9 10)-anthracene hydrochloride crystallizes immediately after crystallization from methanol it melts at 320°-322°C. 

The discovery that Lewis acids can promote Diels-Alder reactions has become a powerful tool in synthetic organic chemistry. Yates and Eaton [4] first reported the remarkable acceleration of the reactions of anthracene with maleic anhydride, 1,4-benzoquinone and dimethyl fumarate catalyzed by aluminum chloride. The presence of the Lewis-acid catalyst allows the cycloadditions to be carried out under mild conditions, reactions with low reactive dienes and dienophiles are made possible, and the stereoselectivity, regioselectivity and site selectivity of the cycloaddition reaction can be modified [5]. Consequently, increasing attention has been given to these catalysts in order to develop new regio- and stereoselective synthetic routes based on the Diels-Alder reaction. 

Lewis-Acid Catalyzed. Recently, various Lewis acids have been examined as catalyst for the aldol reaction. In the presence of complexes of zinc with aminoesters or aminoalcohols, the dehydration can be avoided and the aldol addition becomes essentially quantitative (Eq. 8.97).245 A microporous coordination polymer obtained by treating anthracene- is (resorcinol) with La(0/Pr)3 possesses catalytic activity for ketone enolization and aldol reactions in pure water at neutral pH.246 The La network is stable against hydrolysis and maintains microporosity and reversible substrate binding that mimicked an enzyme. Zn complexes of proline, lysine, and arginine were found to be efficient catalysts for the aldol addition of p-nitrobenzaldehyde and acetone in an aqueous medium to give quantitative yields and the enantiomeric excesses were up to 56% with 5 mol% of the catalysts at room temperature.247... 

The reactor was a 1 liter stainless steel rotating autoclave. In these experiments the ratio of anthracene oil to coal was 3 1. Coal (50 g) impregnated with catalyst (1% Sn as SnC ) was mixed with sand (200 g). The autoclave was pressurized with hydrogen to 10 MPa at room temperature and heated (ca 7°C/minute) to the final reaction temperature (450°C). The pressure at reaction temperature was approximately 25 MPa. 

Lebreton, R. Brunet, S. Perot, G., et al., Deactivation and characterization of hydrotreating NiMo/AL203 catalyst coked by anthracene. Studies in Surface Science and Catalysis, 1999. 126 p. 195. 

One of the most commonly studied systems involves the adsorption of polynuclear aromatic compounds on amorphous or certain crystalline silica-alumina catalysts. The aromatic compounds such as anthracene, perylene, and naphthalene are characterized by low ionization potentials, and upon adsorption they form paramagnetic species which are generally attributed to the appropriate cation radical (69, 70). An analysis of the well-resolved spectrum of perylene on silica-alumina shows that the proton hyperfine coupling constants are shifted by about four percent from the corresponding values obtained when the radical cation is prepared in H2SO4 (71). The linewidth and symmetry require that the motion is appreciable and that the correlation times are comparable to those found in solution. 

Several methods can be employed to convert coal mto liquids, with or without the addition of a solvent or vehicle. Those methods which rely on simple pyrolysis or carbonization produce some liquids, but the main product is coke or char Extraction yields can be dramatically increased by heating the coal over 350°C in heavy solvents such as anthracene or coal-tar oils, sometimes with applied hydrogen pressure, or the addition of a catalyst Solvent components which are especially beneficial to the dissolution and stability of the products contain saturated aromatic structures, for example, as found in 1,2,3,4 tetrahydronaphthalene Ilydroaromatic compounds are known to transfer hydrogen atoms to the coal molecules and, thus, prevent polymerization... 

Linn and Halpern later found that the active catalyst in the ketone and anthracene hydrogenation reactions of Pez was likely to be Ru( 2-H2)(H)2(PPh3)3 (Fig. 3.6) [67]. For example, cyclohexanone is converted to cyclohexanol under mild conditions in toluene (see Table 3.3). The TOF depends on the substrate concentration, and the rate law for the catalytic reaction was determined to be given by Eq. (2), with k= 1.3x 10 M-1 s-1 at 20°C. 

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. 

Allylchlorosilanes also react with naphthalene to give isomeric mixtures of poly-alkylated products. However, it is difficult to isolate and purify the products for characterization because the products possess similar boiling points. The alkylation of anthracene with allylchlorosilanes or vinylchlorosilanes is not possible because of the deactivation of aluminum chloride catalyst by complex formation with anthracene. 

Double-bond isomerization reaction of simple olefins requires strong basic catalysts. Various catalyst systems have been reported for this reaction. They include sodium-organosodium catalysts prepared in situ by reacting an excess of sodium with a reactive organic compound, such as o-chlorotoluene or anthracene as reported by Pines and co-workers 5-8). 

Catalysts and reaction conditions used are generally similar to those used for olefin isomerization. Catalysts reported are sodium-organosodium catalysts prepared in situ by reaction of a promoter such as o-chloro-toluene or anthracene with sodium 19-24), alkali metal hydrides 20,21), alkali metals 22), benzylsodium 26), and potassium-graphite 26). These catalysts are strong bases that can react with alkylaromatics to replace a benzylic hydrogen [Reaction (2)]. 

Yields are based on olefin charged. One mole of aromatic was reacted with 0.2 mole of olefin. Potassium, 1.7 g., with 1 g. of anthracene was used as a catalyst. 

In a study of the carbonization (- 525°C) and graphitization (- 2500°C) of thianthrene in comparison with anthracene, it was shown that the carbons of the heterocycle are nongraphitable between 1200°C and 2500°C, sulfur was evolved continuously (85MI3). Aluminum chloride catalytic carbonization of thianthrene has also been studied. At lower temperatures than without a catalyst, thianthrene produced an isotropic coke catalytic co-carbonization with anthracene and 9,10-dihydroanth-racene gave mosaic and needle cokes, respectively (80MI6, 80MI7). Po-ly(arylene sulfides) were shown to be produced by aluminum chloride treatment of thianthrene at 180-350°C (79URP659582). 

It may be mentioned briefly that also for other catalytic oxidations, e.g., for those of ethylene and of anthracene, multicomponent catalysts proved to be very effective. For the anthracene oxidation, the following... 

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