A Green, Guided-Inquiry Based Electrophilic Aromatic Substitution for the Organic Chemistry Laboratory

We developed an alternative electrophilic aromatic substitution reaction for the organic chemistry teaching laboratory. The experiment is an electrophilic iodination reaction of salicylamide, a popular analgesic, using environmentally friendly reagents—sodium iodide and household bleach. Further, we designed the lab as a guided-inquiry experiment, asking the students first to predict the orientation of the substitution reaction. After synthesizing the product, the students are asked to determine its structure using FT-IR spectroscopy. The choice of this method of characterization was intentional because of the utility of infrared spectroscopy in determining substitution patterns on aromatic rings and also because it requires students to analyze the fingerprint region of the spectrum. Given that most classroom instruction on IR focuses on functional group determination, we believe this is an added benefit to this experiment.