Transmutation of Scent: An Evaluation of the Synthesis of Methyl Cinnamate, a Commercial Fragrance, via a Fischer Esterification for the Second-Year Organic Laboratory
Jacob H. Steele, Marie X. Bozor, Gregory R. Boyce
Abstract
The synthesis of a commercial fragrance, methyl cinnamate, via Fischer esterification was evaluated for use as a second-year organic chemistry course. The experiment utilizes trans-cinnamic acid, a commercial flavoring that possesses a mild honey floral odor, as an inexpensive starting material. Both the starting material and the product are listed as GRAS (Generally Recognized as Safe) for use in foods and fragrances. The high-yielding experiment enables students to explore concepts of flavor and fragrances, transmutation of scent, catalysis, green chemistry, NMR spectroscopy, thin layer chromatography (TLC), and acid–base extractions. In addition to the commonly employed sulfuric acid catalyst, alternative conditions were developed using p-toluenesulfonic acid monohydrate as an easier to handle catalyst, and conditions for performing both reactions under microwave irradiation are also reported. The experiment was analyzed in a second-year organic chemistry laboratory over six semesters.