Effect of water and lipophilic alcohols or amines on the 4-dodecylbenzenesulfonic acid-catalyzed esterifications, trans-esterifications and amidations

4-Dodecylbenzenesulfonic acid (DBSA) was employed in the esterification of oleic acid (OA) and the trans-esterification of oleic oil (OO) with 1-butanol as alcohol in the presence of various degrees of excess water. Under these conditions DBSA was found to be a highly active esterification catalyst regardless of excess water content, but was found to be a less effective for trans-esterification reactions. Lipophilic alcohols of differing straight and branched C3-6 chains were also tested on mixtures of OA/water (1:1) in DBSA-catalyzed esterifications; OO/water (1:1) in trans-esterifications; and OA/OO/water (1:1:1) in simultaneous esterifications and trans-esterifications. While longer straight chain alcohols generally gave a two-fold increase in yield of their corresponding alkyl oleates to 80%+, we observed a doubling from 30–50% to 60–95% of alkyl oleate yield for the OO/OA/water mixture. DBSA-catalyzed amidations of OO and methyl oleate emulsions in water were conducted with 1-butyl and 1-heptyl amine where it was found that the more lipophilic the ester moiety the higher the yield of alkyl amide.