The acylation of 3-(2-naphthyl)-D-alanine (I) with phenylacetyl chloride (II) and bis(trimethylsilyl)acetamide in THF gives the expected N-phenylacetyl derivative (III), which is methylated with NaH and methyl iodide in THF yielding the N-methyl derivative (IV). The reaction of (IV) with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (WSC), HOBT and ammonium hydroxide affords the corresponding alaninamide (V), which by reaction with bis(trifluoroacetoxy)iodobenzene (BTI) in acetonitrile is converted into the monoacylated gemdiamine (VI). The condensation of (VI) with cis-2-(1H-indol-3-ylcarboxamido)cyclohexanecarboxylic acid (VII) by means of WSC and HOBT in DMF affords the target compound as a diastereomeric mixture that is separated by preparative RP-HPLC.