A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [PYC 4 SO 3 H][HSO 4 ], and characterized using FT-IR spectroscopy, the N 2 adsorption/desorption analysis (BET), thermal analysis (TG/ DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

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Preparation of a novel heterogeneous acidic catalyst by impregnation of alumina support by N-(4-sulfonic acid)butyl triethylammonium hydrogen sulfate ([Et 3 NC 4 SO 3 H][HSO 4 ]), 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.

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