Solvent Effects on the Kinetics of the Dakin-West Reaction

摘要

The rate of the Dakin-West reaction have been investigated in Mesub2/subSO, THF and CHsub3/subCN at the temperature range (55–70) are reported. First order rate constants were obtained in each case. A Bronsted slope was found to be equal -0.0277 indicates that the transition state is very reactant-like and the proton has barely moved. Further, the solvent effect was considered from two points of mechanistic view: the thermodynamic transfer function of Mesub2/subSO to CHsub3/subCN and THF where the rate was found to be fast in Mesub2/subSO and slow in THF and CHsub3/subCN and the Kirkwood-Buff preferential solvation with aqueous Mesub2/subSO, CHsub3/subCN and THF. The techniques supported the proposed transition state structure.