Solvent-free enzymatic synthesis of fatty alkanolamides

An environmentally benign and volume efficient process for enzymatic production of alkanolamides is described. Immobilized Candida antarctica lipase B, Novozym (R) 435, was used to catalyze the condensation of lauric acid with monothanolamine. The raction temperature of 90 degrees C was required to keep the reactants in a liquid state. Atepwise addition of the amine minimized problems caused by the formation of a highly viscous amine/fatty acid ion pair. The enzyme was both very active and stable under the reaction conditions, with about half of the activity remaining after 2 weeks. The maximum amide yield obtained when using equimolar amounts of the r4eaction wa 75%, which could be increased to 95% upon water removal. Special precautions to avoid co-distillation of the amine were required, Two different stratagies to avoid the amine loss are presented.