Br[C:2]1[N:10]([CH2:11][C:12]2[CH:17]=[CH:16][C:15]([Cl:18])=[CH:14][CH:13]=2)[C:9]2[C:8](=[O:19])[N:7]([CH2:20][CH2:21][CH2:22][O:23][Si:24]([C:27]([CH3:30])([CH3:29])[CH3:28])([CH3:26])[CH3:25])[C:6](=[O:31])[N:5]([CH3:32])[C:4]=2[N:3]=1.[CH2:33]([NH2:36])[CH2:34][CH3:35]>C(O)C.O>[Si:24]([O:23][CH2:22][CH2:21][CH2:20][N:7]1[C:8](=[O:19])[C:9]2[N:10]([CH2:11][C:12]3[CH:13]=[CH:14][C:15]([Cl:18])=[CH:16][CH:17]=3)[C:2]([NH:36][CH2:33][CH2:34][CH3:35])=[N:3][C:4]=2[N:5]([CH3:32])[C:6]1=[O:31])([C:27]([CH3:29])([CH3:28])[CH3:30])([CH3:25])[CH3:26]Step 1 8-Bromo-1-(3-((tert-butyldimethylsilyl)oxy)propyl)-7-(4-chlorobenzyl)-3-methyl-1H-purine-2,6(3H,7H)-dione (0.25 g, 0.46 mmol, intermediate 77) and propan-1-amine (1.44 mL, 9.2 mmol) were combined in ethanol (5 mL) and heated at reflux for 24 h. The reaction was cooled to room temperature, diluted with water (75 mL) and extracted with ethyl acetate (3×75 mL). The combined organic extracts were dried with magnesium sulfate, filtered and the solvent evaporated under reduced pressure to yield a light golden oil. The oil was purified using a 25 g silica gel column eluted with 20% ethyl acetate/hexanes to give 1-(3-((tert-butyldimethylsilyl)oxy)propyl-7-(4-chlorobenzyl)-3-methyl-8-(propylamino)-1H-purine-2,6(3H,7H)-dione (0.15 g, 63% yield) as a white solid. LCMS retention time=5.013 min and 97% purity, LCMS MH+ 520.
Wird geladen…