Following the procedure described for the preparation of N-((1S)-1-{[((1S)-3-chloro-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)amino]carbonyl}-3-methylbutyl)-4-methoxy-1H-indole-2-carboxamide but substituting N2-(tert-butoxycarbonyl)-N1-((1S)-3-chloro-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)-5-methyl-l-norleucinamide and making no other critical variations provided a crude yellow foam. This material was purified by Biotage MPLC (25 M column, 2.5–3.5% methanol/chloroform) to afford 307 mg (73%) of the title compound as a white solid. 1H NMR (DMSO-d6) δ 11.57 (s, 1H), 8.59 (d, J = 8 Hz, 1H), 8.41 (d, J = 4 Hz, 1H), 7.64 (s, 1H), 7.37 (s, 1H), 7.09 (t, J = 8 Hz, 1H), 7.00 (d, J = 8 Hz, 1H), 6.49 (d, J = 8 Hz, 1H), 4.59 (s, 2H), 4.44 (m, 1H), 4.35 (m, 1H), 3.87 (s, 3H), 3.08 (m, 2H), 2.26 (m, 1H), 2.07 (m, 1H), 1.98 (m, 1H), 1.70–1.51 (m, 5H), 1.25 (m, 2H), 0.88 (d, J = 4 Hz, 3H), 0.86 (d, J = 4 Hz, 3H); MS (ESI+) for C25H33ClN4O5m/z 505.2 (M + H)+; HRMS (ESI+) calcd for C25H33ClN4O5+H1 505.2212, found 505.2204.