A novel nanostructured catalyst namely silica-bonded imidazolium-sulfonic acid chloride (SBISAC) was prepared, and fully characterized by several techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). The nano-compound was applied as an efficient and heterogeneous catalyst in the synthesis of hexahydroquinolines via the one-pot multi-component condensation of arylaldehydes with dimedone (5,5-dimethylcyclohexane-1,3-dione), beta-ketoesters and ammonium acetate under mild and solvent-free conditions. (C) 2015 Elsevier B.V. All rights reserved.