Reaction Steps
To an iced slurry of (2S,4R)-4-(biphenyl-4-yl)-1-((S)-2-(tert-butoxycarbonylamino)-3,3-dimethylbutanoyl)-4-(methylthio)pyrrolidine-2-carboxylic acid (26 mg, 0.049 mmol), (1R,2S)-1-amino-N-(cyclopropylsulfonyl)-2-vinylcyclopropanecarboxamide, p-toluenesulfonate salt, H2O (24.85 mg, 0.059 mmol), and HATU (28.1 mg, 0.074 mmol) in DCM (1 mL) was added N,N-diisopropylethylamine (0.026 mL, 0.148 mmol). The formed colorless slurry was stirred at room temperature overnight (it became light yellow solution). Diluted with DCM, quenched with 5% citric acid. The separated organic layer was washed with sat. sodium citrate and brine, dried over MgSO4, filtered, evaporated in vacuo. The residue was purified by prep-HPLC to afford the desired product tert-butyl (S)-1-((2S,4R)-4-(biphenyl-4-yl)-2-((1R,2S)-1-(cyclopropylsulfonylcarbamoyl)-2-vinylcyclopropylcarbamoyl)-4-(methylthio)pyrrolidin-1-yl)-3,3-dimethyl-1-oxobutan-2-ylcarbamate (18 mg, 0.024 mmol, 49.3% yield) as a white solid. 1H NMR (500 MHz, MeOD) ppm 1.03-1.12 (m, 11H), 1.25 (d, J=3.36 Hz, 2H), 1.43-1.48 (m, 1H), 1.50 (s, 9H), 1.88 (dd, J=8.09, 5.34 Hz, 1H), 1.92 (s, 3H), 2.16-2.27 (m, 1H), 2.38 (t, J=11.29 Hz, 1H), 2.82 (dd, J=11.90, 6.10 Hz, 1H), 2.90-2.99 (m, 1H), 3.97-4.04 (m, 2H), 4.48-4.53 (m, 1H), 5.03 (d, J=10.99 Hz, 1H), 5.13 (d, J=10.68 Hz, 1H), 5.30 (d, J=17.40 Hz, 1H), 5.70-5.81 (m, 1H), 7.37 (t, J=7.02 Hz, 1H), 7.46 (t, J=7.48 Hz, 2H), 7.57-7.64 (m, 4H), 7.64-7.73 (m, 2H). LC-MS (retention time: 3.28 min, method B), MS m/z 739 (M+H).
