Novel acidic ChCl/TFA DES as reaction medium and catalyst for Biginelli and Hantzsch reactions

Novel deep eutectic solvent (DES) using Choline Chloride (ChCl) as the hydrogen bond acceptor and triflouroacetic acid (TFA) as hydrogen bond donor (1.0:1.5 molar ratio) was prepared at room temperature and characterized by FT- IR and 1H NMR spectroscopy. Also, this novel acidic RTDES (room temperature deep eutectic solvent) was successfully used both as a reaction medium and catalyst in Biginelli, Biginelli-like, and Hantzsch reactions. The procedures have the advantages of high yields, short reaction times and easy work-up as well as relatively mild conditions and they do not require additional catalysts and organic solvents. The DES could be easily recycled without considerable loss of activity even after more than three cycles.