Reaction Steps
Phenylmethyl 4-{(2R)-2-[([(2R)-2-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}-2-(3-pyridinyl)ethyl]{[(1,1-dimethylethyl)oxy]carbonyl}amino)methyl]-3,4-dihydro-2H-chromen-6-yl}-2-(phenyloxy)benzoate (Example 191, 69 mg, 0.086 mmol) was stirred over a suspension of 10% Pd/C (7 mg) in ethanol (5 mL) under a hydrogen atmosphere for 15 hours. Solids were removed by filtration through Celite®, and the filtrate was concentrated in vacuo. The carboxylic acid intermediate was collected as a colorless oil (25 mg, 41%): 1H NMR (300 MHz, CD3OD) δ 8.66-8.58 (m, 2 H), 7.99 (d, 1 H), 7.92 (d, 1 H), 7.58-7.54 (m, 2 H), 7.51-7.41 (m, 2 H), 7.37-7.34 (m, 2 H), 7.21-7.16 (m, 2 H), 7.10 (d, 2 H), 6.86 (d, 1 H), 5.27-5.15 (m, 1 H), 4.38-4.31 (m, 1 H), 3.86-3.54 (m, 4 H), 2.96-2.90 (m, 2 H), 2.13-2.00 (m, 1 H), 1.87-1.75 (m, 1 H), 1.56 (d, 9 H), 1.00 (s, 9 H), 0.18 (d, 3 H), 0.00 (s, 3 H). The carboxylic acid intermediate (25 mg, 0.04 mmol) was stirred in an excess of 4M HCl in dioxane at room temperature for 18 hours. The volatile components were removed by rotary evaporation, and the residue was washed with dichloromethane. After drying under vacuum, the title compound was collected as the di-hydrochloride salt (16 mg, 80%): 1H NMR (300 MHz, CD3OD) δ 9.04 (broad s, 1 H), 8.89 (broad s, 1 H), 8.77 (d, 1 H), 8.15 (t, 1 H), 8.00 (d, 1 H), 7.46 (d, 1 H), 7.38-7.33 (m, 4 H), 7.14-7.08 (m, 2 H), 6.98 (d, 3 H), 5.45 (d, 1 H), 4.50 (t, 1 H), 3.76-3.55 (m, 5 H), 3.52-3.35 (m, 2 H), 2.99-2.85 (m, 2 H), 2.18-2.11 (m, 1 H), 1.85-1.75 (m, 1 H); MS m/z 497.2 (MH+ of the free base).
