S. H. Leung, S. Angel
Oct 1, 2004
Citations
0
Influential Citations
40
Citations
Journal
Journal of Chemical Education
Abstract
In this experiment (E)- and (Z)-1-(4-bromophenyl)-2-phenylethene are synthesized by a solvent-free Wittig reaction. The reaction is effected by grinding the reactants in a mortar with a pestle. Both the E and Z isomers of the product are produced as evidenced by thin-layer chromatography and 1H NMR analysis. The E isomer is isolated by crystallization with ethanol in this experiment. In addition to learning about the Wittig reaction, students are also introduced to the ideas of mechanochemistry and green chemistry. This experiment can be extended to include 1H NMR analysis of the products. Students can observe the difference in the coupling constants of the alkenyl protons between the E and Z isomers of 1-(4-bromophenyl)-2-phenylethene.