Reaction Steps
A mixture of N1-[(2R,3S)-3-amino-2-hydroxy-4-phenylbutyl)-N1-(cyclopentyloxy)-4-methoxy-1-benzenesulfonamide (Step 1, Example 48), (73 mg, 0.168), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (34 mg, 0.18 mmol), N-hydroxybenzotriazole (24 mg, 0.18 mmol), and (2S)-4-amino-4-oxo-2-[(2-quinolinylcarbonyl)amino]butanoic acid hydrochloride (57 mg, 0.18 mmol, Eur. Pat. Appl. EP 432694) was combined under an Argon atmosphere at ambient temperature in anhydrous dimethylformamide (2 mL). After addition of N,N-diisopropylethylamine (896 μL, 0.513 mmol), the mixture was stirred for 16 hours. The reaction solvent was removed in vacuo and the residue was dissolved in ethyl acetate. The solution was transferred to a separatory funnel and washed twice with 1N sodium hydrogen sulfate. The combined aqueous layers were extracted with ethyl acetate. The combined organic layers were washed with 5% aqueous potassium carbonate and brine, dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo. The residue was purified on a preparative TLC plate (20×20 cm, 1000 μM) eluting with 97:3 chloroform:methanol. The product band was removed, eluted with 3:1 methylene chloride:methanol, filtered, and evaporated in vacuo. The residue was triturated with hexane and diethyl ether. The slurry was evaporated in vacuo to a residue and dried under high vacuum to provide (2S)-N1-((1S,2R)-1-benzyl-3-(cyclopentyloxy)[(4-methoxyphenyl)sulfonyl]amino-2-hydroxypropyl)-2-[(2-quinolinylcarbonyl)amino]butanediamide (49 mg, 41%) as a white solid. H1-NMR (chloroform-D3): 1.52 (m, 4H), 1.75 (m, 4H), 2.82 (m, 5H), 3.10 (m, 1H), 3.82 (b, 1H), 3.84 (s, 3H), 3.91 m, 1H), 4.29 (m, 1H), 4.78 (m, 1H), 4.95 (m, 1H), 5.76 (b, 1H), 6.22 (b, 1H), 7.00 (m, 5H), 7.12 (d, 2H), 7.22 (d, 1H), 7.60 (m, 1H), 7.75 (m, 3H), 7.83 (d, 1H), 8.14 (m, 2H), 8.25 (d, 1H), 9.15 (d, 1H). MS(ESI): 704 (M+H).
