Chemical fixation of CO2: efficient synthesis of quinazoline-2,4(1H, 3H)-diones catalyzed by guanidines under solvent-free conditions

Guanidines were proved to be efficient catalysts for the chemical fixation of carbon dioxide with 2-aminobenzonitriles under solvent-free conditions. Notably, the catalysts with low loading worked well for a variety of 2-aminobenzonitriles. As a result, quinazoline-2,4(1H, 3H)-diones by employing present protocol were obtained in good yields under mild conditions. This process represents an alternative approach for the greener chemical fixation of CO₂ to afford valuable compounds.