Hydroxyalkylation of benzene derivatives by benzaldehyde in the presence of acid zeolites

Condensation of benzene, anisole and N,N-dimethylaniline with benzaldehyde has been carried out in the presence of a USY zeolite (Si/Al 1.7.5). A comb ined study of the product distribution present in the liquid phase (di- and triarylmethanes together with N-benzylated byproducts in the case of dimet hylaniline) as well as the organic material entrapped inside the zeolite mi cropores (triphenylmethane or trityl ions) has established that there is a direct relationship between the reactivity of the arene and the conversion of benzaldehyde, percentage of diarylmethanes in the liquid phase and popul ation of trityl cations. A hydride transfer from triarylmethanes to diarylm ethyl cation intermediates has been proposed as a key step for the simultan eous presence of trityl cations adsorbed in the solid and diarylmethanes in the liquid phase. (C) 1998 Elsevier Science B.V. All rights reserved.