[C:1]([O:4][C@H:5]([CH3:27])[CH2:6][CH2:7][CH2:8][CH2:9][N:10]1[C:19](=[O:20])[C:18]2[N:17]([CH2:21][O:22][CH2:23][CH3:24])[C:16](Br)=[N:15][C:14]=2[N:13]([CH3:26])[C:11]1=[O:12])(=[O:3])[CH3:2].[S-2:28].[Na+].[Na+]>C(O)C>[C:1]([O:4][C@H:5]([CH3:27])[CH2:6][CH2:7][CH2:8][CH2:9][N:10]1[C:19](=[O:20])[C:18]2[N:17]([CH2:21][O:22][CH2:23][CH3:24])[C:16]([SH:28])=[N:15][C:14]=2[N:13]([CH3:26])[C:11]1=[O:12])(=[O:3])[CH3:2]To a stirring solution of (R)-1-(5-acetoxyhexyl)-8-bromo-7-ethoxymethyl-3-methylxanthine (prepared as for CT13430) (1.77 g, 4.0 mmol) in ethanol (100 ml) was added sodium sulfide (4.48 g, 80 mmol). The reaction mixture was stirred at 90° C. for 1 hour. After evaporation of the solvent under reduced pressure, the crude product was purified by flash chromatography on silica gel eluting with ethyl acetate-methanol (7:1) to provide (R)-1-(5-acetoxyhexyl)-7-ethoxymethyl-8-mercapto-3-methylxanthine. This product was dissolved in methanol (100 ml). A solution of hydrogen chloride in ether (1.0 M, 1.0 ml) was added and stirred at room temperature for 24 hours. After evaporation of the solvent under reduced pressure. The crude product was purified by flash chromatography on silica gel eluting with ethyl acetate-methanol (4:1) to provide (R)-7-ethoxymethyl-1-(5-hydroxyhexyl)-8-mercapto-3-methylxanthine (0.61 g, 51% yield) as a white solid.
Wird geladen…