Vernonia Oil: Conversion to a Mixture of Tertiary Amines Including N,N‐Dimethyl‐(12S,13R)‐epoxy‐cis‐9‐octadecenyl Amine

Abstract

Vernonia galamensis is a new potential industrial oilseed crop found in tropical Africa. It is the source of a naturally epoxidized oil called vernonia oil (VO) which is extracted from the seed of the plant. In this study VO was used as the starting material for the synthesis of a mixture of amines, with the major product amine being N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine. VO was transesterified via a base catalyzed methanolysis using sodium methoxide to yield VO methyl esters (VOME). Aminolysis of the VOME with dimethylamine as reagent and solvent under reflux conditions afforded the tertiary amides, with N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amide as the major product. The mixture was then subjected to metal hydride reduction with lithium aluminum hydride in diethylether under reflux conditions to obtain the desired amine mixture including N,N-dimethyl-(12S,13R)-epoxycis-9-octadecenyl amine. Electron impact mass spectrometry was used to characterize the mixture of amines. Additionally, proton NMR, 13 C NMR, and FTIR were used for characterization of N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine. To further confirm the conversion of VO to the amines, the quaternary ammonium salts were synthesized and characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.