Friedel-Crafts benzylation aromatic hydrocarbons

Diphenylmethane, (C6H5)2CH2, is best prepared from benzyl chloride, C6H5CH2CI, and benzene by the Friedel and Crafts synthesis. It melts at 26° and boils at 262°. Homo-logues of this compound can be prepared from aldehydes and aromatic hydrocarbons by the action of sulphuric acid. Thus, aldehyde or acetal and benzene when shaken with sulphuric acid give diphenyl-methyl-methane (unsymmetrical diphenylethane) ... 

There is a specific interest in Ga-containing MTS, which stems from the high selectivity to aromatics shown by Ga-containing zeolites in the catalytic conversion of hydrocarbons [140-143]. For example, the commercial Cyclar process, where C3-C5 alkanes are dehydrocycHzed to yield aromatic hydrocarbons, proceeds over [Ga]-ZSM-5, whereas conventional ZSM-5 aluminosilicates mainly yield paraffins. It has also been shown that Ga-containing MCM-41 is very active for Friedel-Crafts type benzylation and acylation reactions [143,144]. 

Very highly crosslinked, substantially aromatic networks containing methylene bridges fall into several categories hydrocarbon networks, phenol-formaldehyde and similar networks, and furan-based networks. The hydrocarbon networks have not yet found broad industrial applications despite the fact that they have been known for over a century. Traditionally, hydrocarbon aromatic networks were prepared [437, 438] under Friedel-Crafts conditions using monomers such as benzyl chloride [439] ... 

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