Coupling between asparagine amide (I) and N-Fmoc-1-amino-cyclohexanecarboxylic acid (II) afforded dipeptide amide (III). Deprotection of the Fmoc group of (III) to give (IV) was carried out by treatment with piperidine in DMF. Subsequent coupling of dipeptide (IV) with the protected phenylalanine derivative (V) using diisopropyl carbodiimide (DIC) and HOBt furnished tripeptide (VI), and further cleavage of the Fmoc group provided (VII). Acylation of (VII) with tert-butyl oxalyl chloride (VIII) yielded amide (IX). The tert-butyl ester groups of (IX) were finally cleaved by treatment with trifluoroacetic acid.