Preparation of Oil of Wintergreen from Commercial Aspirin Tablets. A Microscale Experiment Highlighting Acyl Substitutions

Abstract

A single-pot procedure for the preparation of methyl salicylate (oil of wintergreen) from commercial aspirin tablets has been developed. The synthesis proceeds via a tandem transesterification–Fischer esterification using acidic methanol and can be carried out using either conventional or microwave heating. The experiment helps demonstrate acyl substitution chemistry while generating student interest in chemistry. The experiment can be performed in approximately three hours, and the product can be used to demonstrate acquisition and interpretation of 1 H and 13 C NMR spectroscopy.