Dual Studies on a Hydrogen–Deuterium Exchange of Resorcinol and the Subsequent Kinetic Isotope Effect

An efficient laboratory experiment
has been developed for undergraduate
students to conduct hydrogen–deuterium (H–D) exchange
of resorcinol by electrophilic aromatic substitution using D2O and a catalytic amount of H2SO4. The resulting
labeled product is characterized by 1H NMR. Students also
visualize a significant kinetic isotope effect (kH/kD ≈ 3 to 4) by adding
iodine tincture to solutions of unlabeled resorcinol and the H–D
exchange product. This method is highly adaptable to fit a target
audience and has been successfully implemented in a pedagogical capacity
with second-year introductory organic chemistry students as part of
their laboratory curriculum. It was also adapted for students at the
advanced high school level.