[CH2:1]([O:3][C:4]([C:6]1[NH:7][CH:8]=[C:9]2[CH:18]([C:19]3[O:20][C:21]([S:24][C:25]4[NH:29][C:28]5[CH:30]=[CH:31][C:32]([O:34][Si](C(C)(C)C)(C)C)=[CH:33][C:27]=5[N:26]=4)=[CH:22][CH:23]=3)[C:17]3[C:16](=[O:42])[CH2:15][CH2:14][CH2:13][C:12]=3[NH:11][C:10]=12)=[O:5])[CH3:2].CCCC[N+](CCCC)(CCCC)CCCC.[F-]>O1CCCC1>[CH2:1]([O:3][C:4]([C:6]1[NH:7][CH:8]=[C:9]2[CH:18]([C:19]3[O:20][C:21]([S:24][C:25]4[NH:29][C:28]5[CH:30]=[CH:31][C:32]([OH:34])=[CH:33][C:27]=5[N:26]=4)=[CH:22][CH:23]=3)[C:17]3[C:16](=[O:42])[CH2:15][CH2:14][CH2:13][C:12]=3[NH:11][C:10]=12)=[O:5])[CH3:2]9-{5-[5-(tert-Butyl-dimethyl-silanyloxy)-1H-benzimidazol-2-ylsulfanyl]-furan-2-yl}-8-oxo-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylic acid ethyl ester (376 mg, 0.62 mmol) is treated with tetra-N-butylammonium fluoride (162 mg 0.62 mmol) in tetrahydrofuran (5 ml) for 5 hours at room temperature. The reaction mixture is then concentrated under reduced pressure and the residue is purified on a silicagel column (40 g) eluted with a mixture of dichloromethane and methanol (9/1, v/v). The fractions containing the expected product are concentrated under reduced pressure and the residue is washed with acetonitrile (20 ml), pentane (20 ml), diisopropylether (20 ml) and dried under vacuum to yield 154 mg of 9-[5-(5-hydroxy-1H-benzoimidazol-2-ylsulfanyl)-furan-2-yl]-8-oxo-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylic acid ethyl ester as a light yellow powder. Yield=50%. Analytical LC/MS (method C): m/z=489 (negative ion mode [M−H]−), m/z=491 (positive ion mode [M+H]+).
読み込み中…