ABSTRACT
University of Bologna, Dipartimento di Chimica Industriale e dei Materiali, Viale
Risorgimento 4, 40136 Bologna, Italy. INSTM, Research Unit of Bologna. A member of Concorde CA and Idecat NoE (6FP of the EU)
fabrizio.cavani@unibo.it
Abstract The reaction of phenol benzoylation catalyzed by a H-β zeolite (Si/Al ratio 75) has been studied, with the aim of determining the reaction scheme. The only primary product was phenylbenzoate, which then reacted consecutively to yield o-and phydroxybenzophenone and benzoylphenylbenzoate isomers, via both intermolecular and intramolecular mechanisms. Introduction Friedel-Crafts acylation of aromatic substrates is widely employed for the synthesis of aryl ketones, intermediates of relevant industrial importance for the production of drugs, fragrances and pesticides. The acylating compounds are acyl halides, and homogeneous Lewis-type acids (typically, metal halides) are the catalysts employed (1). The latter are, however, used in large amounts, often larger than the stoichiometric requirement; also, recovery of the metal halides at the end of the reaction is not possible, and big amounts of waste streams are co-generated. Therefore, the environmental impact of these processes makes highly desirable the development of new technologies that employ heterogeneous, recyclable catalysts, and of reactants that generate more environmentally friendly co-products (2).
