A Novel Friedel-Crafts Acylation Reaction of Anisole for Production of 4-Methoxyacetophenone with High Selectivity and Sufficient Reusability of Mordenite Zeolite Catalyst

Abstract

Zeolite catalyzed Friedel-Crafts reactions were examined using acetic anhydride as an acetylating agent and an acetic acid as a solvent. It revealed that the reaction of anisole smoothly occurred quantitatively for 3 h using mordenite zeolite with SiO2/Al2O3 = 200, and with SiO2/Al2O3 = 110, the increasing of Bronsted acidity allowed to completely react within 2 h. Furthermore the selectivity of 4-methoxyacetophenone (4-MA) among the isomers was found to be quantitative, no by-products and/or isomers were not detectable. With the excellent recyclability and reusability, the mordenite zeolite exhibited at least 30 times quantitatively both conversion of anisole and selectivity of 4-MA. The mordenite catalysts of fresh and the used after 30 times were characterized. This opportunity obviously indicates the sufficient shape selective catalyst of mordenite zeolite and gives a green synthetic tool for heterogeneous acylation reaction.