Reaction Steps
Step 10 (A): Preparation of (2R,4R)-tert-butyl 2-((1S,2S)-2-(3-(benzamido)-5-methylbenzamido)-1-(tert-butyldimethylsilyloxy)-3-(3,5-difluorophenyl)propyl)-4-propoxypyrrolidine-1-carboxylate. To a solution of 3-(((1S,2S)-1-((2R,4R)-1-(tert-butoxycarbonyl)-4-propoxypyrrolidin-2-yl)-1-(tert-butyldimethylsilyloxy)-3-(3,5-difluorophenyl)propan-2-yl)carbamoyl)-5-methylbenzoic acid (Preparation G, 26 mg, 0.037 mmol) in dichloromethane (1 mL) was added Hunig's base (15 mg, 0.114 mmol) to make a clear solution and HATU (18 mg, 0.05 mmol) was then added. After stirring for 20 min, the reaction mixture was added dipropylamine (6 mg, 0.057 mmol) and the reaction mixture was stirred at rt for 6 h. The crude mixture was purified by silica gel Flash Chromatography (0% to 10% to 30% EtOAc/Hexane step gradient) to give 27 mg of the title compound (90% yield): 1H NMR (CDCl3, 500 MHz) δ ppm 0.02 (3H, s), 0.06 (3H, s), 0.71 (3H, m), 0.85 (9H, s), 0.88 (3H, m), 0.96 (3H, m), 1.48-1.54 (12H, m), 1.67 (2H, m), 1.74 (2H, m), 2.03-2.09 (1H, m), 2.19 (1H, m), 2.38 (3H, s), 2.62 (1H, m), 2.94 (1H, m), 3.13 (2H, brd s), 3.26-3.36 (3H, m), 3.43 (2H, brd s), 3.76 (1H, m), 3.97 (1H, m), 4.04-4.07 (1H, m), 4.10-4.12 (1H, m), 4.58 (1H, m), 6.59 (1H, m), 6.76 (2H, d, J=5 Hz), 7.25 (1H, s), 7.60 (1H, s), 7.70 (1H, s), 7.98 (1H, brd s). MS (ESI) (M+H)+ 774.63.
