合成路线1

The alkylation of 2-methylbenzimidazole (I) with 4-chloro-3-nitrobenzyl chloride (II) provided adduct (III). Displacement of the chlorine atom of (III) with methylamine furnished the nitro aniline (IV), which was further reduced to phenylenediamine (V) by catalytic hydrogenation over Raney-Ni. Acylation of (V) by N-(4-cyanophenyl)glycine (VI) using N,N'-carbonyldiimidazole as the activating reagent yielded amide (VII). The bis-benzimidazole compound (VIII) was then produced by cyclization of (VII) in refluxing HOAc. Finally, Pinner reaction of nitrile (VIII) with ethanolic HCl, followed by treatment of the resulting imidate with ammonium carbonate, provided the target amidine.