To a solution of N-[(1S)-2-[((1S)-3-(benzyloxy)-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)amino]-1-(cyclohexylmethyl)-2-oxoethyl]-4-methoxy-1H-indole-2-carboxamide (80 mg, 0.13 mmol) in EtOH (3 mL) was added 10% Pd/C (50 mg), and the suspension was hydrogenated at an ambient temperature under H2 (1 atm balloon) for 5 h. The catalyst was removed by filtration, and the solvents were evaporated in vacuo to yield the crude product, which was purified by Biotage flash chromatography, eluting with 2–10% methanol/dichloromethane to afford the title compound, 37 mg, 55% as a white solid. 1H NMR (400 MHz, MeOD) δ 7.19 (s, 1H), 7.05 (t, J = 8.0 Hz, 1H), 6.93 (d, J = 8.1 Hz, 1H), 6.41 (d, J = 7.8 Hz, 1H), 4.52–4.59 (m, 2H), 4.27 (m, 2H), 3.83 (s, 3H), 3.08–3.21 (m, 2H), 2.47 (m, 1H), 2.13–2.24 (m, 1H), 1.92–2.03 (m, 1H), 1.53–1.79 (m, 9H), 1.31–1.45 (m, 1H), 1.04–1.29 (m, 3H), 0.81–1.02 (m, 2H); MS (APCI+) for C27H36N4O6m/z 513.2. (M + H)+; anal. calcd for C27H36N4O6· 0.8 H2O: C, 61.53; H, 7.19; N, 10.63. Found: C, 61.83; H, 7.12; N, 10.27.