13-Aryl-12H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraone derivatives were synthesized by the one-pot condensation of 2-hydroxy-1,4-naphthoquinone and aldehydes under solvent-free conditions with good yields in the presence of silica-supported sodium hydrogen sulfate as heterogeneous catalyst. The catalyst is easily prepared, reusable, low-cost, and environment-friendly under the reaction conditions.