N-((1S)-3-Chloro-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)-N-[(4-methoxy-1H-indol-2-yl)carbonyl]-l-phenylalaninamide
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 N-(tert-butoxycarbonyl)-N-((1S)-3-chloro-2-oxo-1-{[(3S)-2-oxopyrrolidin-3-yl]methyl}propyl)-l-phenylalaninamide and making noncritical variations provided a crude green solid. This material was purified by Biotage flash chromatography, eluting with methanol/dichloromethane to afford the title compound as a white solid, 300 mg, 91%. 1H NMR (400 MHz, DMSO-d6) δ 11.52 (d, J = 2.0 Hz, 1H), 8.68 (d, J = 7.8 Hz, 1H), 8.61 (d, J = 7.8 Hz, 1H), 7.61 (s, 1H), 7.37 (d, J = 7.1 Hz, 2H), 7.31 (d, J = 1.8 Hz, 1H), 7.26 (t, J = 7.6 Hz, 2H), 7.16 (t, J = 7.2 Hz, 1H), 7.07 (t, 1H), 6.97 (d, J = 8.1 Hz, 1H), 6.49 (d, J = 7.6 Hz, 1H), 4.68 (m, 1H), 4.38–4.49 (m, 3H), 3.88 (s, 3H), 2.97–3.17 (m, 4H), 2.20–2.32 (m, 1H), 2.02–2.14 (m, 1H), 1.93–2.02 (m, 1H), 1.52–1.69 (m, 2H); MS (APCI±) for C27H29N4O5Cl m/z 526.0 (M + H)−.