The title compound is obtained by solid-phase synthesis using a 2-chlorotrityl chloride resin: Attachment of N-Fmoc-3-amino-3-(3-quinolinyl)propionic acid (I) to the chlorotrityl resin provides the protected amino acid-bound resin (II). Removal of the N-Fmoc group of (II) is achieved by treatment with piperidine in DMF to yield (III). Acylation of amine (III) with N-Fmoc-isonipecotic acid (IV) employing HATU furnishes amide (V). After Fmoc group deprotection in (V) with piperidine, the resultant amine resin (VI) is coupled to the guanidino acid (VII), producing resin (VIII). The title compound is finally cleaved from the resin by treatment with trifluoroacetic acid.