Zeolite-catalyzed acylation of heterocyclic compounds — VI. One-step synthesis of 3-(benzofuran-2-carbonyl)pentane-2,4-dione from 2-acetylbenzofuran over HY-zeolite

The reaction between 2-acetylbenzofuran and acetic anhydride at 60°C in the presence of HY-zeolite ( Si Al = 16 ) led to a single final product: 3-(benzofuran-2-carbonyl)pentane-2,4-dione resulting from two consecutive acylation steps on the side chain. It was obtained in a 90% purity at around 50% conversion of 2-acetylbenzofuran. Other minor products and intermediates were also identified. A mechanism is proposed to account for the formation of the various products. The catalyst can be regenerated and reused.