Synthesis of Methyl Oleate Catalyzed by Bronsted Acid Ionic Liquids [BSMim]HSO_4

An ionic liquid stable in water,1-(3-sulfonic acid)butyl-imidazole hydrosulfate with an alkanesulfonic acid group was prepared.Synthesis of methyl oleate from oleic acid catalyzed by the ionic liquid was studied.Ionic liquid[BSMim]HSO4 exhibited good catalytic activity and stability.Optimal esterification condition was obtained as follows:n(methanol):n(oleic acid)=3:1,reaction temperature 75℃,reaction time 4h,dosage of ionic liquid = 20.0% of the oleic acid weight.The results showed that[BSMim]HSO4 has good activity for esterification of oleic acid and methanol,the yield of methyl oleate reached 85.3%.The ionic liquid was stable and could be repeatedly used.