反应详情

1.7 g (12.48 mmol) of potassium carbonate were added at 60° C. to a suspension of 2.2 g (7.8 mmol) of 7-benzyl-3-propylxanthine (prepared according to Example 4a) in 70 ml of dimethylformamide and the mixture was stirred at this temperature for one hour. 1.3 ml (10.14 mmol) of 2-propoxyethyl chloride were then added dropwise and the mixture was stirred at 80° C. for 10 hours. 1.2 ml of methanol and 14 ml of water were then added, and the mixture was allowed to stand overnight, treated with a further 70 ml of water and extracted three times using 84 ml of methyl tert-butyl ether each time. The combined organic phases were washed twice with 42 ml of water each time, dried using magnesium sulfate and concentrated under reduced pressure. The crude product was purified by flash chromatography on a silica gel column, dichloromethae/methanol (19/0.1).

1. stirringthe mixture was stirred at 80° C. for 10 hours
2. waitto stand overnight
3. extractionextracted three times
4. washThe combined organic phases were washed twice with 42 ml of water each time
5. customdried
6. concentrationconcentrated under reduced pressure
7. customThe crude product was purified by flash chromatography on a silica gel column, dichloromethae/methanol (19/0.1)