EFFICIENT SYNTHESIS OF XANTHENE USING A DEEP EUTECTIC SOLVENT CATALYST UNDER SOLVENT-FREE CONDITIONS

Abstract

Several choline chloride–based deep eutectic solvents were synthesized in this study via conventional heating. The obtained catalysts exhibited intermolecular hydrogen bonding, as evidenced by FTIR spectra. In xanthene synthesis, the choline chloride–FeCl₃ DES showed the highest catalytic activity; optimal conditions were 80°C, 2 h, and 10 mol% catalyst (relative to benzaldehyde) under solvent-free conditions. Yields decreased for benzaldehyde derivatives bearing substituents compared with unsubstituted benzaldehyde