Triethanolamine–sodium acetate as a novel deep eutectic solvent for promotion of tetrahydrodipyrazolopyridines synthesis under microwave irradiation

Abstract

Deep eutectic solvents like ionic liquids were used as solvent or catalyst in organic synthesis. In this work, a novel deep eutectic solvent containing triethanolamine and sodium acetate was prepared and studied by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), potential of hydrogen (pH), viscosity and conductivity. This deep eutectic solvent was applied for the synthesis of tetrahydrodipyrazolopyridines as an efficient reusable catalyst under microwave irradiation. The advantages of this method include easy catalyst preparation, low catalyst consumption, short reaction time, excellent product yields and safe operation.