Coupling between ethyl 5-aminoindole-2-carboxylate (I) and 5-nitrobenzofuran-2-carboxylic acid (II) by means of HBTU affords amide (III). Subsequent ethyl ester hydrolysis under alkaline conditions yields the carboxylic acid (IV). Ring opening of the cyclopropane-fused compound (V) with anhydrous HCl in EtOAc leads to the chloromethyl compound (VI). Acid (IV) is finally coupled to amine (VI) in the presence of EDC to furnish the title compound.