反应详情

A mixture of 2.0 g (5.3 mmol) of 8-(3,4-dimethoxyphenylethynyl)-3-ethyl-1-prop-2-ynyl-3,7-dihydropurine-2,6-dione, potassium carbonate (0.83 g, 6 mmol) and methyl iodide (0.6 ml, 10 mmol) in dimethylformamide (20 ml) was stirred at room temperature for 0.5 h (TLC-control: dichloromethane/methanol, 9.5:0.5). The product was precipitated by addition of water (100 ml), filtered under reduced pressure, was washed with water and dried at 70° C. Further purification was achieved by column chromatography on silica gel (eluent: dichloromethane/methanol, 9.5:0.5) and subsequent crystallization from dichloromethane/petroleum ether. Yield: 1.76 g, 80% (crude product); m.p.: 221.5° C.

1. customThe product was precipitated by addition of water (100 ml)
2. filtrationfiltered under reduced pressure
3. washwas washed with water
4. customdried at 70° C
5. customFurther purification
6. customwas achieved by column chromatography on silica gel (eluent: dichloromethane/methanol, 9.5:0.5) and subsequent crystallization from dichloromethane/petroleum ether