Reaction Steps
A solution of (2R,6S,13aS,14aR,16aS,Z)-2-(biphenyl-4-yl)-6-(tert-butoxycarbonylamino)-5,16-dioxo-2-(propylsulfonyl)-1,2,3,5,6,7,8,9,10,11,13a,14,14a,15,16,16a-hexadecahydrocyclopropa[e]pyrrolo[1,2-a][1,4]diazacyclopentadecine-14a-carboxylic acid (995 mg, 1.406 mmol) and CDI (274 mg, 1.687 mmol) in tetrahydrofuran (20 mL) was heated to gentle reflux for 3 h. Cooled down to rt, cyclopropanesulfonamide (204 mg, 1.687 mmol) and DBU (0.424 mL, 2.81 mmol) were added and the reaction continued at r.t. for 4 h. Removed the solvent in vacuo. The residue was taken up in EtOAc. Washed it with 5% citric acid and brine, dried over MgSO4, filtered, evaporated. The residue was purified by BIOTAGE® system, eluted with gradient 10%˜50% acetone-hexane to afford the desired product tert-butyl (2R,6S,13aS,14aR,16aS,Z)-2-(biphenyl-4-yl)-14a-(cyclopropylsulfonylcarbamoyl)-5,16-dioxo-2-(propylsulfonyl)-1,2,3,5,6,7,8,9,10,11,13a,14,14a,15,16,16a-hexadecahydrocyclopropa[e]pyrrolo[1,2-a][1,4]diazacyclopentadecin-6-ylcarbamate (827 mg, 0.999 mmol, 71.1% yield) as a white solid. 1H NMR (400 MHz, MeOD) δ ppm 0.87-1.09 (m, 5 H) 1.06-1.22 (m, 2 H) 1.24-1.40 (m, 3 H) 1.39-1.66 (m, 17 H) 1.64-1.79 (m, 3 H) 1.82-2.03 (m, 2 H) 2.39 (d, J=8.53 Hz, 1 H) 2.65 (br. s., 1 H) 2.75-3.01 (m, 3 H) 3.05-3.27 (m, 2 H) 4.14 (dd, J=10.04, 6.53 Hz, 1 H) 4.43 (d, J=10.54 Hz, 2 H) 4.54 (s, 1 H) 5.11 (br. s., 1 H) 5.34 (d, J=10.54 Hz, 1 H) 5.70 (q, J=8.53 Hz, 1 H) 7.35-7.43 (m, 1 H) 7.48 (t, J=7.65 Hz, 2 H) 7.63 (d, J=7.53 Hz, 2 H) 7.72 (d, J=8.28 Hz, 2 H) 7.98 (d, J=8.28 Hz, 2 H). LC-MS (retention time: 1.92 min, method A), MS m/z 811 (M+H).
