Synthesis and Characterization of Bronsted Acidic Ionic Liquid Based on Ethylamine as an Efficient Catalyst for the Synthesis of Xanthene Derivatives under Solvent-Free Conditions

Ethylammonium N-sulfonic acid chloride, a sulfonic acid functionalized ionic liquid, was prepared, characterized and used as an efficient catalyst for synthesis of various xanthene derivatives by condensation between aldehydes and dimedone or 2-naphthol under solvent-free conditions. This procedure has several advantages such as, easy preparation of the catalyst, easy work-up, high yields, short reaction times, and avoidance of toxic organic solvents.