合成路线1

Nitration of 1-(4-chlorophenyl)-1-cyclopropanecarboxylic acid (I) with fuming HNO3 produced the 3-nitro derivative (II). The chloride group of (III) was then displaced with methylamine to give the nitro aniline (III). Coupling of (III) with pyrrolidine (IV) by means of TBTU yielded amide (V). The nitro group of (V) was reduced by catalytic hydrogenation over Pd/C to afford the phenylenediamine (VI), which was subsequently acylated by N-(4-cyanophenyl)glycine (VII), yielding amide (VIII). Benzimidazole (IX) was then obtained by cyclization of (VIII) in refluxing HOAc. Pinner reaction of nitrile (IX) with ethanolic HCl produced the imidate (X), which was finally converted to the target amidine by treatment with ammonium carbonate.