Biphasic Continuous Esterification of Choline Chloride-Based Deep Eutectic Solvents using ICHEM Technology: A Step toward New Hydrotropes with Potential Anticorrosive Properties.

Abstract

Impact in Continuous Flow Heated Mechanochemistry (ICHEM) technology was used for the first biphasic continuous flow esterification of choline chloride-based deep eutectic solvents (DESs) with nonmiscible acetic, hexanoic, and octanoic anhydrides, resulting in the synthesis of novel hydrotropic DESs. The reaction was first optimized in batch using acetic anhydride, and then scaled up to continuous flow in an 80 mL WAB Research Lab ICHEM reactor, achieving 90-95% yields at lab scales of 50-100 g. The physicochemical properties of the three new DESs were analyzed, revealing that esterification via the ICHEM process had minimal impact on these properties compared to the conventional batch method. Furthermore, the potential of these new hydrotropic DESs as anticorrosive agents was evaluated, demonstrating their effectiveness as corrosion inhibitors.