[CH3:1][O:2][C:3]1[C:8]2[N:9](C(OCC)=O)[C:10](=[O:12])[NH:11][C:7]=2[CH:6]=[CH:5][CH:4]=1.[OH-].[K+].IC[CH2:22][CH2:23][C:24]([CH3:29])([N+:26]([O-:28])=[O:27])[CH3:25]>CN(C=O)C.O>[CH3:1][O:2][C:3]1[C:8]2[NH:9][C:10](=[O:12])[N:11]([CH2:22][CH2:23][C:24]([CH3:29])([N+:26]([O-:28])=[O:27])[CH3:25])[C:7]=2[CH:6]=[CH:5][CH:4]=14.0 g (17 mmol) ethyl 7-methoxy-2-oxo-2,3-dihydro-benzimidazol-1-carboxylate in DMF are combined with 85% potassium hydroxide solution (3.3 g, 51 mmol) while being cooled with the ice bath. After 30 minutes a solution of 5.2 g (21 mmol) 1-iodo-4-methyl-4-nitro-pentane in DMF is added and the mixture is stirred overnight at ambient temperature. The reaction mixture is diluted with water and extracted with ethyl acetate. The combined organic phases are washed with water, dried and freed from the solvent. The oil remaining is purified by chromatography on a silica gel column (cyclohexane/ethyl acetate gradient). Yield: 0.5 g (8%); mass spectroscopy: [M+H]+=366.
読み込み中…
