Putting the squeeze on imine synthesis: citrus juice as a reaction medium in the introductory organic laboratory

This article highlights a less hazardous and energy-efficient organic synthesis utilizing freshly squeezed citrus juice as a solvent that was developed for a sophomore-level laboratory course. The experiment enables students to engage with key green chemistry principles, including waste prevention, atom economy, the use of safer chemicals, and energy efficiency. In the experiment, 4-nitrobenzaldehyde and 4-methoxyaniline are reacted in various fruit juices to synthesize a Schiff base (imine), which is then characterized using proton NMR spectroscopy. Students also explore the reaction mechanism for imine formation and undertake the reduction of the imine to a secondary amine, observing a significant color change due to the disruption of conjugation. This laboratory experience reinforces core organic chemistry concepts while fostering practical skills and reflection on sustainable chemical practices.

Full citation: Nigam, M., Tuttle, D., Morra, B., Dicks, A. P., & Rodriguez, J. (2023). Putting the squeeze on imine synthesis: citrus juice as a reaction medium in the introductory organic laboratory. Green Chemistry Letters and Reviews, 16(1), 2185107. https://doi.org/10.1080/17518253.2023.2185107