[CH3:1][C@@H:2]1[CH2:19][CH2:18][CH2:17][C@H:16]([NH:20][C:21](=[O:27])[O:22][C:23]([CH3:26])([CH3:25])[CH3:24])[C:15]2[CH:28]=[C:11]([CH:12]=[CH:13][N:14]=2)[C:10]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[NH:4][C:3]1=[O:29].C1C(=O)N([Br:37])C(=O)C1>C(#N)C>[Br:37][C:8]1[CH:7]=[CH:6][C:5]2[NH:4][C:3](=[O:29])[C@H:2]([CH3:1])[CH2:19][CH2:18][CH2:17][C@H:16]([NH:20][C:21](=[O:27])[O:22][C:23]([CH3:25])([CH3:24])[CH3:26])[C:15]3[CH:28]=[C:11]([CH:12]=[CH:13][N:14]=3)[C:10]=2[CH:9]=1To a suspension of 45G (616 mg, 1.558 mmol) in acetonitrile (15.200 ml) in a sealed vial was added NBS (277 mg, 1.558 mmol). The reaction was sealed and heated at 75° C. overnight. Additional NBS (300 mg, 1.686 mmol) was added and heat at 75° C. overnight. The mixture was concentrated and purified by silica gel chromatography to afford 137A as a white solid (664 mg, 90%). MS (ESI) m/z: 476.0 (M+H)+.
Wird geladen…