The Shape-Selective Acylation of 2-Methoxynaphthalene, Catalyzed by Zeolites Y, Beta and ZSM-12

Abstract

The Friedel-Crafts acylation of 2-methoxynaphthalene (2MN) was investigated using zeolites USY, Beta and ZSM-12 as catalysts under batch conditions at 100 and 180 °C. Two ketone isomers, 1-acetyl-2-methoxynaphthalene (1AC) and 2-acetyl-6-methoxynaphthalene (2AC) were produced; the selectivity of the reaction could be influenced by the zeolite used. USY produced only the 1AC isomer whereas Beta and ZSM-12 produced both. Selective synthesis of 2AC was achieved by optimization of the reaction conditions using zeolite Beta as the catalyst. It was also observed that the 1AC ketone is unstable in contact with acid zeolite catalysts and undergoes protiodeacylation, a reaction previously only observed in the presence of strong mineral acids.