反应详情

2.1 g of 3-methyl-7-propylxanthine, 0.7 g of 1-chloro-heptan-6-one and 1.4 g of potassium carbonate are heated at 120° C. in 15 ml of dimethylformamide for 7.5 hours, while stirring. After the mixture has been concentrated under reduced pressure, the residue is poured into 100 ml of H2O, the mixture is extracted three times with 100 ml of CHCl3 each time, and the combined chloroform extracts are treated with 1 N sodium hydroxide solution and water in succession and dried over sodium sulfate. The concentration residue is chromatographed in a column using silica gel 60 and chloroform/ethanol (9:1) as the mobile phase. After recrystallization from petroleum ether/diisopropyl ether (3:1), 2.45 g (=76.6% yield) of 1-(6-oxoheptyl)-3-methyl-7-propylxanthine of melting point 69-70° C. are obtained.

1. concentrationAfter the mixture has been concentrated under reduced pressure
2. additionthe residue is poured into 100 ml of H2O
3. extractionthe mixture is extracted three times with 100 ml of CHCl3 each time
4. additionthe combined chloroform extracts are treated with 1 N sodium hydroxide solution and water in succession
5. dry with materialdried over sodium sulfate
6. customThe concentration residue is chromatographed in a column