Reaction Steps
To a solution of (S)-2-((S)-3-acetamido-3-((R)-sec-butyl)-2-oxopyrrolidin-1-yl)-4-phenylbutanoic acid (Preparation B, 25 mg, 0.069 mmol) in dichloromethane (1 mL) was added Hunig's base (27 mg, 0.21 mmol) to make a clear solution and HATU (34 mg, 0.090 mmol) was then added. After stirring for 1 h, to the reaction mixture was added (1S,2S)-1-((R)-2-(4-methoxybenzyl)-1,2,3,4-tetrahydroisoquinolin-3-yl)-2-amino-3-(3,5-difluorophenyl)propan-1-ol (Preparation A, 33.5 mg, 0.076 mmol) and the reaction mixture was stirred at rt overnight. Solvent was removed and the crude mixture was purified by silica gel Flash Chromatography to give 50 mg of the title compound: 1H NMR (CD3OD, 500 MHz) δ 0.68 (3H, d, J=5 Hz), 0.94-1.08 (4H, m), 1.61-1.66 (2H, m), 1.94 (3H, s), 2.01-2.20 (4H, m), 2.46 (1H, m), 2.60-2.69 (2H, m), 2.76-2.94 (2H, m), 3.00 (1H, m), 3.07 (1H, dd, J=5, 15 Hz), 3.22 (1H, m), 3.46 (1H, dt, J=5, 10 Hz), 3.62-3.69 (3H, m), 3.74 (3H, s), 3.82 (1H, m), 4.02 (1H, d, J=15 Hz), 4.14 (1H, dd, J=5, 10 Hz), 4.72 (1H, m), 6.70 (1H, m), 6.81 (2H, d, J=10 Hz), 6.87 (2H, d, J=10 Hz), 6.96 (1H, d, J=5 Hz), 7.08-7.13 (6H, m), 7.17-7.20 (2H, m), 7.24 (2H, d, J=5 Hz). MS (ESI)(M+H)+ 781.39.
