In this paper, we describe the preparation of novel heterogeneous solid acid catalyst by immobilization of sulfuric acid on functionalized hexagonal mesoporous silica. This catalyst was successfully synthesized and characterized using FT-IR, SEM, EDS, TGA, XRD, and BET techniques. The catalytic activity of 5-oxo-1- (3-(triethoxysilyl)propyl)pyrrolidine-3-carboxylic sulfuric anhydride immobilized on HMS (HMS/APTES-IA-SO3H) was studied for the one-pot synthesis of 1-amidoalkyl-2-naphthols and 2-substituted benzimidazoles. The synthesized catalyst could be easily recovered from the reaction mixture and reused.