Condensation between 2-(3,4-dimethoxyphenyl)ethylamine (I) and 4-chlorobenzaldehyde (II) in refluxing toluene affords imine (III). Then, Pictet-Spengler cyclization of imine (III) in the presence of trifluoroacetic acid leads to the tetrahydroisoquinoline (IV). This is further acylated in boiling acetic anhydride to produce the target acetamide.