Esterification in ionic liquids: The influence of solvent basicity

Wells TP, Hallett JP, Williams CK, Welton T

(Chemical Equation Presented) The second-order rate constant (k 2) for the esterification of methoxyacetic acid with benzyl alcohol is reported in a range of ionic and molecular solvents. The solvent effects on esterification rate are examined by using a linear solvation energy relationship based on the Kamlet-Taft solvent scales (α, β, and π*). It is shown that the hydrogen bond basicity of the solvent is the dominant parameter in determining the esterification rate and that the best rates are achieved in low basicity solvents. © 2008 American Chemical Society.