Condensation of N,N'-dibenzylethylenediamine (I) with ethyl 2,3-dibromopropionate (II) in the presence of Et3N in toluene at 80 C gave, after acidification, piperazine (III). Then, hydrogenolytic N-debenzylation in the presence of Pd/C provided ethyl piperazine-2-carboxylate (IV), which was selectively alkylated at position 4 with 1 equivalent of triphenylmethyl chloride in the presence of Et3N at -10 C to give (V). Subsequent alkylation with 2,4-dichlorobenzyl chloride (VI) in the presence of K2CO3 and a catalytic amount of KI provided (VII). Removal of the N-trityl group by treatment with HCl in either acetone or ethanol afforded piperarine (VIII), which was N-methylated by reaction with formaldehyde and formic acid in refluxing MeOH. Finally, the resulting compound (IX) was converted into the imidazoline on treatment with ethylenediamine and trimethylaluminum in refluxing toluene.