Kinetic study of aromatic hydrocarbons acylation by substituted benzoic acids.

The direct acylation of aromatic hydrocarbons by some substituted benzoic a cids occurs with high yields under Friedel-Crafts reaction conditions. The acylation with ortho and pars alkylbenzoic acids is particularly interestin g because of the increasing effect of this substitution on the reaction rat e. Our proposition is that the alkyl moiety with cc-H is responsible for the r elatively high reaction rates of conversion. A carbanionic-like species sta bilized by the Lewis acid is held to be the reaction intermediate. It is fo rmed in presence of the aluminum halide that behaves not only as a catalyst but also as a reactant.