Abstract:

A comprehensive medicinal chemistry experiment performed by students in our school majoring in pharmaceutical engineering and pharmaceutics is introduced. In this experiment, L-3, 4-dimethoxyphenylalanine methyl ester was synthesized from L-3, 4-dimethoxyphenylalanine and methanol by using dichlorosulfoxide as the dehydrating agent at room temperature. Then, methyl-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline-3-carboxylate was prepared from L-3, 4-dimethoxyphenylalanine methyl ester and paraformaldehyde via the Pictet-Spengler reaction using dichloromethane as the solvent and trifluoroacetic acid as a catalyst. The structure was characterized using ¹H NMR spectroscopy and MS. This experiment is beneficial to students for the following reasons: stimulating independent thinking and cultivating research-mindedness, comprehensively training both technical lab skills and structural identification of organic compounds, and mastering the principles and methods of scientific research on drug synthesis.

Key words: L-3, 4-Dimethoxyphenylalanine, Paraformaldehyde, Paraformaldehyde, Pictet-Spengler reaction, Methyl 6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline-3-carboxylate