A novel [DBN] [HSO4] difunctionalized bronsted acidic ionic liquid-promoted Knoevenagel condensation followed by cyclization protocol has been developed for the first time by a successive reaction of aldehydes, and dimedone to afford xanthene derivatives in high to excellent yields at 80οC temperature. The ionic liquid provided the capability to allow a variability of functional groups, short reaction times, easy workup, high yields, recyclability of the catalyst and solvent-free conditions, thus providing economic and environmental advantages.
