Alumina Supported Acidic Ionic Liquid: Preparation, Characterization, and Its Application as Catalyst in the Synthesis of 1,8-dioxo-octahydroxanthenes

Abstract

Preparation of a novel heterogeneous acidic catalyst by impregnation of alumina support by N-(4-sulfonic acid)butyl triethylammonium hydrogen sulfate ([Et3NC4SO3H][HSO4]), an acidic ionic liquid, and its primary application as a solid acidic supported catalyst in the synthesis of 1,8-dioxo-octahydroxanthenes by reaction of dimedone with aromatic aldehydes are described. Characterization of the catalyst was performed by FT-IR, BET, TG/DTG, and XRD techniques. The results showed that the catalyst has high activity and the desired products were obtained in high yields. Moreover, the recovered catalyst was found to be reusable and a considerable catalytic activity still could be achieved after third run.