Synthesis alkylbenzene

Boveri, M., Marquez-Alvarez, C., Laborde, M.A., and Sastre, E. (2006) Steam and add dealumination of mordenite charaderization and influence on the catalytic performance in linear alkylbenzene synthesis. Catal. Today, 114, 217-225. 

Effenberger, R, Buckel, R, Maier, A. H., and Schmider, J. 2000. Perfluoro-alkanesulfonic acid catalyzed acylations of alkylbenzenes synthesis of alkyl-anthraquinones. Synthesis 1427-1430. 

Figure 5.16 A tubular turbulent divergent-convergent device for alkylbenzene synthesis. 1 - reactor vessel 2 - convergent element 3 - divergent element 4 -cylindrical element 5 - jacket for heating of the initial reaction mixture 6 - jacket for reaction heat removal 7, 8, 9,10, 11 - tubes for the introduction of dry benzene, polyalkylbenzenes, recycled benzene, ethylene, and catalj ic complex, respectively ...

Wolff-Kishner reduction aids in alkylbenzene synthesis... 

Pure bis(alkylbenzene)chromium complexes are best prepared by the chromium vapor route as there is no rearrangement of the alkylbenzene that often accompanies the Fischer synthesis for these compounds. However, the yield of bis(alkylbenzene)chromium compounds are not high, rarely more than 20% polymeric materials accompany the desired product (32, 83, 84). 

Molybdenum and tungsten atoms seem to react with alkylbenzenes more efficiently than chromium atoms yields of 30 to 50% are reported (113). Conventional routes to the synthesis of tungsten-arene complexes are difficult and inefficient so that the ability to prepare these compounds in high yield via tungsten atoms is of special significance. Unfortunately, tungsten has a very high vaporization temperature and the scale of work with its vapor is necessarily limited. 

A cracking process, the dealkylation of alkylbenzenes, became an established industrial synthesis for aromatics production. Alkylbenzenes (toluene, xylenes, tri-methylbenzenes) and alkylnaphthalenes are converted to benzene and naphthalene, respectively, in this way. The hydrodealkylation of toluene to benzene is the most important reaction, but it is the most expensive of all benzene manufacturing processes. This is due to the use of expensive hydrogen rendering hydrodealkylation too highly dependent on economic conditions. 

The transalkylation of fm-alkylbenzenes follows a different route, since they have no abstractable benzylic hydrogen. They were shown to transalkylate by a dealkylation-transalkylation mechanism with the involvement of free ferf-alkyl cations. The exceptional ability of fcrt-alkyl groups to undergo transalkylation led to the extensive utilization of these groups, especially the fm-butyl group, as positional protective groups in organic synthesis pioneered by Tashiro.223... 

An important method of synthesis of alkylbenzenes utilizes an alkyl halide as the alkylating agent and a metal halide, usually aluminum chloride, as... 

Unlike alkylation, acylation is controlled easily to give monosubstitution, because once an acyl group is attached to a benzene ring, it is not possible to introduce a second acyl group into the same ring. Because of this, a convenient synthesis of alkylbenzenes starts with acylation, followed by reduction of the carbonyl group with zinc and hydrochloric acid (Section 16-6). For example, propylbenzene is prepared best by this two-step route because, as we have noted, the direct alkylation of benzene with propyl chloride produces considerable amounts of isopropylbenzene and polysubstitution products ... 

In the acylation of alkylbenzene the product almost always is the para isomer. The synthesis of (4-fert-butylphenyl)ethanone illustrates this as well as, the sequential use of alkylation and acylation reactions ... 

The synthesis of alkylbenzenes may be classified under (a) the Wurtz-Fittig reaction (b) the reduction of aryl aldehydes and ketones and (c) and Friedel-Crafts alkylation reaction. 

The Grignard reagent derived from benzyl chloride undergoes ready alkylation with an alkyl toluene-p-sulphonate, a reaction which provides a further useful synthesis of an alkylbenzene (e.g. pentylbenzene, Expt 6.2). 

Synthesis of unactivated alkylbenzenes labelled with NCA [18F]fluoride... 

The main process for the synthesis of H202 is the autooxidation in an organic solvent such as alkylbenzenes of an alkyl anthraquinol ... 

Dimethyl and diethyl sulfates have been widely employed in the synthesis of alkylbenzenes and alkylnaphthalenes from aryl- and benzyl-type organometallic reagents. The final methyl groups of isodu-rene and pseudocumene are introduced in this manner. The reaction is superior to the Wurtz synthesis (method 9) for the preparation of o- and -diethylbenzenes. n-Propylbenzene obtained from benzylmagnesium chloride and diethyl sulfate ° is contaminated with a "rearranged product, f -ethyltoluene. ... 

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