反应详情

温度

-78 °C

Step 1 8-Bromo-1-(3-((tert-butyldimethylsilyl)oxy)propyl-7-(4-chlorobenzyl)-3-methyl-1H-purine-2,6(3H,7H)-dione (0.50 g, 0.923 mmol, intermediate 77) was dissolved in THF (5 mL) and cooled to −78° C. To the clear solution was slowly added drop wise 2.5 M n-butyllithium in THF (0.35 mL, 0.877 mmol) followed by the immediate addition of isobutyraldehyde (0.42 mL, 4.61 mmol). The reaction was warmed to room temperature and stirred for 1 h. The reaction was diluted with water (75 mL) and extracted with ethyl acetate (3×75 mL). The combined extracts were dried with magnesium sulfate, filtered and the solvent was removed under reduced pressure to yield an oil. The oil was purified using a 25 g silica column eluted with a gradient of 10% to 30% ethyl acetate/hexanes yielding 1-(3-((tert-butyldimethylsilyl)oxy)propyl)-7-(4-chlorobenzyl)-8-(1-hydroxy-2-methylpropyl)-3-methyl-1H-purine-2,6(3H,7H)-dione (0.20 g, 40% yield) as a light golden oil. LCMS retention time=4.923 min and 98% purity, LCMS MH+ 535.

1. temperatureThe reaction was warmed to room temperature
2. extractionextracted with ethyl acetate (3×75 mL)
3. dry with materialThe combined extracts were dried with magnesium sulfate
4. filtrationfiltered
5. customthe solvent was removed under reduced pressure
6. customto yield an oil
7. customThe oil was purified
8. washeluted with a gradient of 10% to 30% ethyl acetate/hexanes