[OH-].[Li+].[CH3:3][C:4]([O:7][CH2:8][CH2:9][C:10]([NH:12][C:13]1[CH:21]=[C:20]2[C:16]([CH:17]=[C:18]([C:31]([O-:33])=[O:32])[N:19]2[C:22]([O:24]CCC(C)(C)C)=[O:23])=[CH:15][CH:14]=1)=[O:11])([CH3:6])[CH3:5].CO.O>C1COCC1>[CH3:3][C:4]([O:24][C:22]([N:19]1[C:20]2[C:16](=[CH:15][CH:14]=[C:13]([NH:12][C:10](=[O:11])[CH2:9][CH2:8][O:7][C:4]([CH3:3])([CH3:6])[CH3:5])[CH:21]=2)[CH:17]=[C:18]1[C:31]([OH:33])=[O:32])=[O:23])([CH3:6])[CH3:5]Lithium hydroxide (0.037 g, 1.55 mmol) was added to a solution of 1-(1,1-dimethylethyl)2-ethyl 6-({3-[(1,1-dimethylethyl)oxy]propanoyl}amino)-1H-indole-1,2-dicarboxylate (0.067 g, 0.155 mmol) in THF:methanol:water/3:1:1 (3 mL). The mixture was heated at 50° C. for 1 hr. The solvent was evaporated and the residue was dissolved in water, acidified with 1N aqueous HCl and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated to give the title compound (0.051 g, 108%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.40 (br. s., 1H), 9.82 (s, 1H), 7.94 (s, 1H), 7.44 (d, 1H), 7.04 (d, 1H), 6.85 (s, 1H), 3.57 (t, 2H), 2.33-2.48 (m, 2H), 1.09 (s, 9H). ES MS: m/z 305 (M+1).
Wird geladen…