[NH2:1][CH2:2][CH2:3][C@@H:4]1[CH2:8][CH2:7][CH2:6][N:5]1[C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10].C(N([CH2:21][CH3:22])CC)C>ClCCl>[CH2:12]([O:11][C:9]([NH:1][CH2:2][CH2:3][C@@H:4]1[CH2:8][CH2:7][CH2:6][N:5]1[C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])=[O:10])[C:22]1[CH:21]=[CH:8][CH:4]=[CH:3][CH:2]=1A mixture of Example 535B (560 mg, 2.62 mmol), benzyloxycarbonylsuccinimide ester (0.783 g, 3.93 mmol, and triethylamine (0.55 mL, 3.93 mmol) in 10 mL of dichloromethane was stirred overnight, concentrated, treated with ethyl acetate, washed with brine, 10% potassium hydrogen sulfate (3×), and brine (3×), dried (MgSO4), filtered, concentrated, and purified by silica gel column chromatography, eluting with 20% ethyl acetate in n-hexane to provide 0.81 g of the desired product. MS (ESI(+)) m/e 347 (M+H)+; 1H NMR (300 MHz, CDCl3) δ 7.28-7.39 (m, 5H), 7.23 (br, 1H), 5.00 (s, 2H), 3.62-3.74 (m, 1H), 3.19-3.29 (m, 2H), 2.92-3.05 (m, 2H), 1.73-1.91 (m, 5H), 1.54-1.62 (m, 1H), 1.38 (s, 9H).
Wird geladen…