Reductive Amination: A Remarkable Experiment for the Organic Laboratory

The synthesis of N-(2-hydroxy-3-methoxybenzyl)-N-p-tolylacetamide is a fast, simple three-step sequence that serves as a useful example of the reductive amination reaction for the organic chemistry laboratory. The first step is a spectacular solvent-free solid-solid reaction between ortho-vanillin and para-toluidine to synthesize an imine in quantitative yield. The imine is reduced to an amine in the second step by sodium borohydride. The amine is acetylated in the third step to form the solid amide in an overall yield of 90%. The entire sequence is performed in an open beaker in less than one hour.