Potassium Carbonate → 3,7-Diethyl-1-(4-hexenyl)xanthine

참여 물질

반응 단계

2.8 g (0.1 mole) of 3,7-diethylxanthine, 15.2 g (0.11 mole) of potassium carbonate and 13.0 g (0.11 mole) of 1-chloro-4-hexene in 600 ml of dimethylformamide were stirred at 110° C. for 18 hours. After cooling down, the mixture was filtered, the filtrate was evaporated under reduced pressure and the residue was taken up in chloroform. The unreacted 3,7-diethylxanthine was removed by extracting with 1N sodium hydroxide solution by shaking, the organic phase was washed to neutrality with water, dried over sodium sulfate and the solvent was distilled off in a rotary evaporator. After drying the solid residue from evaporation, 27.5 g (94.7% of theory) of crude 3,7-diethyl-1-(4-hexenyl)xanthine were obtained, ##STR29## which, after dissolving in 350 ml of chloroform and adding 23.1 g (0.114 mole) of 3-chloroperbenzoic acid (85% pure), was stirred under a nitrogen atmosphere at room temperature for 48 hours. The mixture was then initially extracted by shaking with 10% strength sodium dithionite solution until the iodine-starch reaction disappeared, and then with 10% strength sodium bicarbonate solution, and the solution was washed with water until neutral and free of salt, dried and evaporated under reduced pressure. 29.0 g (100% of theory) of crude 3,7-diethyl-1-(4,5-epoxyhexyl)xanthine were obtained ##STR30## which, after being taken up in a solvent mixture composed of 150 ml of tetrahydrofuran and 100 ml of water and addition of 0.46 ml of perchloric acid (70% strength), was stirred at room temperature for 90 hours. The mixture was then neutralized with saturated sodium bicarbonate solution, the solvent was distilled off under reduced pressure and the residue was chromatographed on silica gel with chloroform as the mobile phase. This produced 26.4 g (86% of theory) of a crystalline product, which was recrystallized from ethyl acetate/petroleum ether, and which was almost pure by thin-layer chromatography.

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