Synthesis of lipophilic antioxidant tyrosol laurate using imidazolium ionic liquid [Bmim]HSO4 as a catalyst.

[Display omitted] • Ionic liquids were first used as catalysts to prepare lipophilic tyrosol laurate. • A high yield of tyrosol laurate (94.24 ± 1.23 %) was obtained by esterification. • Ionic liquid [Bmim]HSO 4 showed excellent catalytic performance and recyclability. • Lipophilic tyrosol laurate showed favorable ABTS radical scavenging ability. • This study proposed a new idea for the synthesis of tyrosol esters. Tyrosol is a natural phenolic compound with potent antioxidant properties in the field of food manufacturing. However, the low lipophilicity of tyrosol limited its application. Therefore, the construction of tyrosol laurate (Tyr-L) could effectively overcome the limitations of tyrosol. In this work, four ionic liquids (ILs) were applied for TYr-L preparation. Among them, the 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO 4) showed the best catalytic performance. The maximum TYr-L yield was achieved (94.24 ± 1.23 %) under the optimal conditions (reaction temperature 119 °C, substrate ratio 1:6.7, IL dosage 9.2 %, and reaction time 12 h). The kinetic and thermodynamic parameters were also evaluated and it was found that E a, Δ H , Δ S , and Δ G were 80.81 kJ·mol−1, 77.63 kJ·mol−1, −82.08 J·(mol·K)−1, and 109.89 kJ·mol−1, respectively. The acidic [Bmim]HSO 4 demonstrated excellent reusability and stability, even after 6 cycles. Furthermore, TYr-L showed superior ABTS radical scavenging ability, which could be further applied in various industrial processes. [ABSTRACT FROM AUTHOR]