Benzene and Alkylbenzenes

All the previous results show that the homolytic amination is not distinguishable from a highly selective electrophilic reaction, with regard to orientation and reactivity. In contrast, the results of Table 6 show that alkylbenzenes are the 

Aromatic substrate N-chloroamine Conversion (%) Yields ) (%) Refs. 

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Coke-oven tar is an extremely complex mixture, the main components of which are aromatic hydrocarbons ranging from the monocyclics benzene and alkylbenzenes to polycycHc compounds containing as many as twenty or more rings. HeterocycHc compounds containing oxygen, nitrogen, and sulfur, but usually only one heteroatom per ring system are present. Small amounts of paraffinic, olefinic, and partly saturated aromatic compounds also occur. 

Benzene (and alkylbenzene) sulphonic acids QH5SO3H Detergents, phenols, dyes... 

The rates of mercuration of a number of aromatic hydrocarbons have been determined using mercuric acetate in acetic acid, in some cases using perchloric acid as catalyst. Rate coefficients for benzene and alkylbenzene have been determined under both conditions at a range of temperatures and the data are gathered in Tables 117 and 118441 -4 8 in the absence of perchloric acid, mercuric acetate reacted with the solvent at a rate that was not insignificant compared with the rate of aromatic mercuration, and a correction was made for this side reaction. 

Another method, formylation with CO and HCl in the presence of AICI3 and CuCl (the Gatterman-Koch reaction), is limited to benzene and alkylbenzenes. ... 

Sanemasa, I., Araki, M., Deguchi, T., Nagai, H. (1981) Solubilities of benzene and alkylbenzenes in water. Methods for obtaining aqueous solutions saturated with vapors in equilibrium with organic liquids. Chem. Lett. 2, 255-258. 

Some bis(salicylaldehydo) complexes of cobalt(II), nickel(II), and cop-per(II), with or without lithium aluminum hydride, are said to catalyze hydrogenation of benzene and alkylbenzenes at 200°C, but the systems appear to be heterogeneous (447). 

There are indications that pure naphthalene (a constituent of mothballs, which are, by definition, toxic to moths) and alkylnaphthalenes are from three to 10 times more toxic to test animals than are benzene and alkylbenzenes. In addition, and because of the low water solubility of tricyclic and polycyclic (polynuclear) aromatic hydrocarbons (i.e., those aromatic hydrocarbons heavier than naphthalene), these compounds are generally present at very low concentrations in the water-soluble fraction of oil. Therefore, the results of this smdy and others conclude that the soluble aromatics of crude oil (such as benzene, toluene, ethylbenzene, xylenes, and naphthalenes) produce the majority of its toxic effects in the enviromnent. 

In addition to benzene and alkylbenzenes several other aromatics (nitrobenzene, aniline, anisole, benzoic acid, etc.) were hydrogenated, usually with much lower rates. Benzoic acid and benzoates gave the corresponding cyclohexyl derivatives, however, in case of acetophenone some deoxygenation was also observed with the Ru-3 catalyst [158]. This latter observation raises some doubts regarding the truly homogeneous nature of the reaction. 

Fuel oils are complex mixtures of aliphatic and aromatic hydrocarbons whose exposure potentials are based on the environmental fate of the individual components of the mixtures, particularly -alkanes, branched alkanes, benzene and alkylbenzenes, naphthalenes, and PAHs. 

Domarfska, U. and Casas, L.M., Solubility of phosphonium ionic liquid in alcohols, benzene and alkylbenzenes, /. Phys. Chem. B, 111, 4109, 2007. 

Sulfonation of Benzene and Alkylbenzenes. Since the main utilization of ben-zenesulfonic acid was its transformation to phenol, the importance of the sulfonation of benzene has diminished. The process, however, is still occasionally utilized since it is a simple and economical procedure even on a small scale. Excess sulfuric acid or oleum is used at 110-150°C to produce benzenesulfonic acid.97,102 Sulfonation of toluene under similar conditions yields a mixture of isomeric toluenesul-fonic acids rich in the para isomer. This mixture is transformed directly to cresols by alkali fusion. 

Benzenes and alkylbenzenes By ring forming reactions Calcium acetate, 60 Chromium carbene complexes, 82 Dicarbonylcyclopentadienylcobalt, 96... 

Olah, G. A. Kuhn, S. J. Selective Friedel-Crafts reactions. I. Boron halide catalyzed haloalkylation of benzene and alkylbenzenes with fluorohaloalkanes. /. Org. Chem. 1964,... 

Fig. 10.3. Electrochromatograms exhibiting the effect of the length of the bare-silica segment on the separation of benzene and alkylbenzenes. Capillary, 100 pm i.d. with a 20 cm ODS segment and a variable-length bare-silica segment of (a), 0 cm (b), 6 cm and (c), 28 cm. Mobile phase, 1.25 mM sodium dihydrogenphosphate, pH 6.0, containing 75% (v/v) acetonitrile. Applied field strength, 625 V/cm. Detection, UV at 254 nm. Solutes 1, benzene 2, toluene 3, ethylbenzene 4, propylbenzene 5, butylbenzene 6, pentylbenzene. Reproduced with permission from Yang and El Rassi [12].

A similar acid catalyzed reaction (equation 41), called hydrodimerization, was found for benzene and alkylbenzenes, which are converted over polyfunctional zeolite catalysts to phenylcyclohexane derivatives89. 

In zeolite-catalysed acylation of aromatic ethers, zeolites have two advantages with respect to benzene and alkylbenzene acylation ... 

Adkins and Kramer hydrogenated benzene and alkylbenzenes to the corresponding cyclohexanes quantitatively over Ni-kieselguhr without solvent at 135-175°C and initial hydrogen pressures of 15.5-18 MPa.11 Examples are shown in eqs. 11.1 and... 

The reaction is known to proceed through activation of the olefin by the catalyst (a rare earth exchanged Y Zeolite In this work) and this activated olefin then reacts with benzene and alkylbenzene. However, since the concentration of activated olefin Is not known, the total concentration of olefin Is used In obtaining kinetic parameters according to the following reactions. 

Malelmide and N-substituted maleimldes undergo photoaddition to benzene and alkylbenzenes to form 2 1 adducts (l. lli Intermediate in the reaction is horaoannular diene (formed by initial 2 + 2 cycloaddition) which subsequently undergoes 2+4 (Dlels-Alder) cycloaddltlon to give dlimide (Reaction 1). 

Under the influence of light, benzene and alkylbenzenes copolymerize with blsmaleimldes by successive 2 -t- 2 and 2 + 4 cycloaddltlon reactIonsL2 l (Reaction 2). Although only the head-to-tall repeating unit Is shown In Reaction 2, It should be recognized that head-to-head and tall-to-tall units can... 

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