A Sustainable Synthetic Approach to Tacrine and Cholinesterase Inhibitors in Deep Eutectic Solvents under Aerobic Conditions

Abstract

An enhanced, sustainable, and efficient method for synthesizing tacrine, achieving a 98% yield, has been developed by replacing volatile organic compounds with more eco-friendly solvents such as deep eutectic solvent (DESs). The optimized protocol scales easily to 3 g of substrate without yield loss and extends successfully to tacrine derivatives with reduced hepatotoxicity. Particularly notable is the synthesis of novel triazole-based derivatives, yielding 90–95%, by integrating an in situ preparation of aryl azides in DESs with N-propargyl-substituted tacrine derivatives. Quantitative metrics validate the green aspects of the reported drug development processes.