Effects of acidity and immiscibility of lactam-based Br?nsted-acidic ionic liquids on their catalytic performance for esterification?

Green Chemistry Pub Date: 2010-02-19 DOI: 10.1039/B921081D

Abstract

Several lactam-based Br?nsted-acidic ionic liquids with different acidities were synthesized and applied to the esterification of carboxylic acids with alcohols. High conversion and perfect selectivity were obtained under mild conditions. Among the ionic liquids investigated, those having a methyl sulfonate anion (which has weaker acidity than those with a tetrafluoroborate anion) afforded the highest activity for esterification. The results indicated that the acidity and immiscibility of Br?nsted-acidic ionic liquids has a synergistic effect on their esterification performance. Furthermore, after removal of water under vacuum, such ionic liquids could be reused several times without substantial loss of activity.

Graphical abstract: Effects of acidity and immiscibility of lactam-based Br?nsted-acidic ionic liquids on their catalytic performance for esterification
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