Kinetics in the thermal and catalytic amidation of C18 fatty acids with ethanolamine for the production of pharmaceuticals

Abstract

For the first time, in this work, C18 fatty acid amidation with equimolar amounts of ethanolamine was studied both in the absence and presence of heterogeneous catalysts in hexane as a solvent at 180 °C. The products, saturated, and especially unsaturated fatty alkanol amides, which exhibit endocannabinoid activities, have been conventionally prepared using toxic and corrosive homogeneous catalysts. The results revealed that noncatalytic thermal amidation of stearic acid proceeding much faster for stearic than for oleic or linoleic acids. Furthermore, microporous H-Beta-150 was the most active catalyst. Mesoporous, H-MCM-41 with lower acidity was also active in oleic acid amidation, whereas more acidic, mesoporous H-MCM-36 gave lower yield due to formation of esteramides.