The reaction of 3-chloro-5-ethyl-2,6-dimethoxybenzoic acid (I) with SOCl2 gives the corresponding acyl chloride (II), which is condensed with N-ethyl-2-(aminomethyl)pyrrolidine (III) in refluxing CHCl3 yielding N-ethyl-2-(3-chloro-5-ethyl-2,6-dimethoxybenzamidomethyl)pyrrolidine (IV). Finally, this compound is treated with BBr3 in methylene chloride.
The reaction of 3,5-dichloro-6-methoxysaliclic acid (I) with refluxing SOCl2 gives the corresponding acyl chloride (II), which is condensed with 1-ethyl-2-(aminomethyl)pyrrolidine (III) in methylene chloride yielding the amide (IV). Finally, this compound is partially demethylated with BBr3 in methylene chloride ether.