[CH2:1]([N:8]1[C:16]2[C:15](=[O:17])[NH:14][C:13](=[O:18])[NH:12][C:11]=2[N:10]=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H-].[Na+].[CH2:21](Br)[CH:22]([CH3:24])[CH3:23]>CN(C)C=O.O.CO>[CH2:1]([N:8]1[C:16]2[C:15](=[O:17])[NH:14][C:13](=[O:18])[N:12]([CH2:21][CH:22]([CH3:24])[CH3:23])[C:11]=2[N:10]=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=11.5 g (6.2 mmol) of 7-benzylxanthine from stage b) were dissolved in 50 ml of dimethylformamide at 50° C. and treated in portions with 0.149 g (6.2 mmol) of sodium hydride and stirred at 50° C. for one hour. 0.67 ml (6.2 mmol) of isobutyl bromide was added dropwise and the mixture was heated to 80° C. After 5 hours, a further 0.2 ml (1.86 mmol) of isobutyl bromide was added and the mixture was stirred for a further 5 hours. 12 ml of water and 5 ml of methanol were then added, the mixture was stirred at room temperature for 2 hours, a further 60 ml of water were added and the mixture was extracted three times using methyl tert-butyl ether. The organic phases were washed with water, dried using magnesium sulfate and concentrated under reduced pressure and the residue was purified by flash chromatography on a silica gel column, dichloromethane/methanol (99/1).
読み込み中…