Multicomponent Synthesis of a N-Protected α-Amino Ester: Ethyl 2-((4-Methoxyphenyl)amino)-3-phenylpropanoate

This laboratory experiment describes the preparation of a N-protected phenylalanine ethyl ester by a zinc-mediated Mannich-like multicomponent reaction between benzyl bromide, p -anisidine, and ethyl glyoxylate. The one-step reaction involves the in situ metallation of benzyl bromide into a benzylzinc reagent and its addition onto imine (Barbier conditions). The multicomponent procedure is suitable for a 4-to-5 h undergraduate organic laboratory.