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

Behzad Khalil,Mona Rasoulian,Aref Atashrazm

doi:10.17159/0379-4350/2019/v72a25

Abstract

N-sulfonated cyclohexylhydantoin (NSCH), a new N-sulfonic acid compound, was prepared and characterized using FT-IR, NMR, 13C 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. Keywords: Hydantoin, N-sulfonated acidic catalyst, chromene, xanthene, hydroquinoline.

Highlights

Common Brønsted acid hydrogen containing catalysts such as sulfuric acid, p-toluene sulfonic acid, hydrochloric acid, hydrofluoric acid and phosphoric acid are used as catalysts to promote many organic synthetic reactions and industrial processes
Catalyst Characterization The structure of the cyclohexylhydantoin-N-sulfonic acid catalyst, which was synthesized as shown in Fig. 1, was characterized by FT-IR, 1H NMR, 13C NMR, TGA, DTG, and UV-Vis analysis
In the case of cyclohexylhydantoinN-sulfonic acid, the OH stretching band of the SO3H functional group appeared as broad bands between 3200 and 3700 cm–1, centred at 3414 cm–1

Summary

Introduction

Common Brønsted acid hydrogen containing catalysts such as sulfuric acid, p-toluene sulfonic acid, hydrochloric acid, hydrofluoric acid and phosphoric acid are used as catalysts to promote many organic synthetic reactions and industrial processes. The above-mentioned Brønsted acid catalysts generally result in homogeneous reaction mixtures, causing problems with separation from reaction media, resulting in some disadvantages such as negative environmental impact, wasting energy and increased chemical wastes production. One of the simplest ways to access solid acidic materials is making use of nitrogencontaining organic compounds and introducing SO3H and HSO4 groups as Bronsetd acid functions into their chemical structure, which make them water soluble and enhance their polarity, which aids their use under solvent-free conditions. Many of such solid acid catalysts have been reported.

Methods

Results

Conclusion