Carbon Dioxide as Building Block in the Synthesis of the Anti‐Infective Agent Hexamine

Abstract Electrochemical reduction of CO 2 in a EMIMBF 4 saturated solution in the presence of small amounts of the ionic liquid tetramethylguanidinium azide (TMGHN 3 ) yield as major product the nonvolatile hexamethylenetetramine (HMTA) also known as hexamine or methenamine. Vestigial concentrations of other reduction products like CO, formic acid and acetic acid were also detected and quantified. Both Cu and Cu/Zn electrodes were tested and presented a similar efficiency towards HMTA production. Electrode modification during CO 2 electro‐reduction, including copper nanoparticle (CuNPs) deposition, is the key feature that facilitates HMTA synthesis.