反应详情

4.7 g of 7-butyl-3-ethylxanthine, 2.8 g of potassium carbonate, and 4.4 g of 1-bromo-6-hydroxy-6-methylheptane are stirred in 100 ml of dimethylformamide at 120° C. for 7 hours. The mixture is filtered hot with suction, the filtrate is concentrated under reduced pressure, the residue is taken up in chloroform, washed first with 2 N sodium hydroxide solution and then with water until neutral and dried over sodium sulphate, the solvent is distilled off under reduced pressure whereupon an oily crude product in virtually quantitative yield is obtained which can advantageously be purified by filtration over a silica gel column using a chloroform/methanol (10:1) mixture as mobile phase, followed by a final recrystallization from diisopropylether with addition of petroleum ether.

1. filtrationThe mixture is filtered hot with suction
2. concentrationthe filtrate is concentrated under reduced pressure
3. washwashed first with 2 N sodium hydroxide solution
4. dry with materialwith water until neutral and dried over sodium sulphate
5. distillationthe solvent is distilled off under reduced pressure whereupon an oily crude product in virtually quantitative yield
6. customis obtained which
7. filtrationcan advantageously be purified by filtration over a silica gel column
8. customrecrystallization from diisopropylether
9. additionwith addition of petroleum ether