The reaction of Nomega'-nitro-D-arginine (I) with 2,2-diphenylacetyl chloride (II) by means of NaOH in THF/water gives the expected Nalpha-diphenylacetyl derivative (III), which is condensed with 4-(ureidomethyl)benzylamine (IV) by means of TBTU and DIEA in THF to yield the corresponding amide (V). Finally, this compound is hydrogenated with H2 over Pd/C in aqueous acetic acid in order to eliminate the Nomega'-nitro group and treated with trifluoroacetic acid to provide the target compound.