Microwave Synthesis of Cationic Fatty Imidazolines and their Characterization

Abstract

AbstractThis paper describes an efficient method for the synthesis of long chain dialkyldiamido imidazolines by the reaction of diethylenetriamine and several fatty acids under non‐solvent microwave irradiation using calcium oxide as support This synthesis required much less time in comparison to conventional thermal condensation and is carried out in an open vessel and the products obtained by this method were found to be in good yields and of high purity. Fatty imidazolines were then quaternized by using dimethyl sulfate as a quaternizing agent and isopropanol as a solvent, to produce cationic imidazolinium salts which were evaluated for yield and cationic content. The instrumental techniques, viz. FT‐IR and 1H NMR verified the formation of imidazolines and its subsequent quaternization. This method produced imidazolines in the very low time of 5–10 min and gave a yield of 89–91% as compared to a very long time of 8–10 h and a lower yield of 75–80% by the conventional thermal condensation method.