Following the procedure described for the preparation of (3S)-3-({N-[(4-methoxy-1H-indol-2-yl)carbonyl]-l-leucyl}amino)-2-oxo-4-[(3S)-2-oxopyrrolidin-3-yl]butyl acetate but substituting N1-((1S)-3-chloro-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)-4-methyl-N2-[(2R)-tetrahydrofuran-2-ylcarbonyl]-l-leucinamide and 2,6-dichlorobenzoic acid and making noncritical variations provided a light amber residue.