Reductive Amination of Aldehyde Ester from Vegetable Oils to Produce Amino Ester in the Presence of Anhydrous Ammonia

Abstract

AbstractReductive amination has been reported in the literature in the presence of amine or liquid ammonia and Ni catalysts for instance. However, to the best of our knowledge it is the first time that anhydrous ammonia was used to produce methyl‐9‐aminononanoate from methyl‐9‐oxononanoate in the presence of hydrogen, methanol and Pd/C catalyst. A yield of 74 % of the primary amino ester (methyl‐9‐aminononanoate) was obtained at 50 °C after 2 h of reaction under 100 bar of hydrogen in the presence of anhydrous ammonia. It was shown that in order to avoid the poisoning of the catalyst, anhydrous ammonia and hydrogen should be added at the beginning of the reaction to maintain the catalytic properties of Pd/C. Moreover, the catalyst was recyclable and the leaching of Pd was rather low under these conditions. These reaction conditions allow the formation of a renewable synthon which can be used in polymer industry.