[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([N:17]1[CH2:23][CH2:22][CH2:21][N:20]([C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25])[CH2:19][CH2:18]1)=[O:16])=[CH:10][CH:9]=2)=[O:5])[CH3:2].C(=O)([O-])[O-].[Cs+].[Cs+].[CH:37](CS([O-])(=O)=O)([CH3:39])[CH3:38]>C(#N)C>[CH2:1]([O:3][C:4]([C:6]1[N:7]([CH:37]([CH3:39])[CH3:38])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([N:17]1[CH2:23][CH2:22][CH2:21][N:20]([C:24]([O:26][C:27]([CH3:29])([CH3:28])[CH3:30])=[O:25])[CH2:19][CH2:18]1)=[O:16])=[CH:10][CH:9]=2)=[O:5])[CH3:2]To a solution of 5-(4-tert-butoxycarbonyl-[1,4]diazepane-1-carbonyl)-1H-indole-2-carboxylic acid ethyl ester (1.55 g, 3.5 mmol) in acetonitrile (25 ml) under an argon atmosphere were added caesium carbonate (2 eq., 2.44 g) and isopropylmethanesulfonate (2 eq., 1.03 g). The mixture was heated at 95° C. (oil-bath temperature) overnight. The mixture was cooled to room temperature and evaporated under reduced pressure. The crude product was purified by column chromatography on silica gel (3:1 heptane/ethyl acetate eluant) to afford the product as a light-brown oil (1.6 g, 93%). MS (m/z): 458.3 (M+H)+.
読み込み中…