2,4-Dioxo-1,3-diazaspiro[4,5]decane-3-sulfonic Acid as a Novel Solid Phase Halogen-free Acid Catalyst: Preparation, Characterization and Evaluation

N-sulfonated cyclohexylhydantoin (NSCH), a new N-sulfonic acid compound, was prepared and characterized using FT-IR, H NMR, C NMR, UV-Vis and TGA analysis. The potential catalyst efficiency was examined, using synthesis of chromene, xanthene and hydroquinoline derivatives under solvent-free conditions. All of the examined model reactions gave excellent yields, and required short reaction times. Simple catalyst preparation and work-up under mild reaction condition, with low cost and the ability to recover the catalyst for reuse without significant loss of activity are some of the notable advantages of the introduced catalyst.