Potassium Carbonate → HCID 13747691, compound

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Reaction Steps

22.2 g (0.1 mol) of 3-methyl-7-(2-oxopropyl)-xanthine from Example 7a are stirred together with 14.8 g (0.11 mol) of 1-chloro-5-hexanone and 15.2 g (0.11 mol) of potassium carbonate in 500 ml of dimethylformamide at 110° C. for 1.5 hours. The mixture is then allowed to cool slowly, with further stirring, and filtered, the salt on the suction filter is rinsed thoroughly with dimethylformamide, the solution is concentrated under reduced pressure, the residue is taken up in 200 ml of methanol, 50 ml of water and 2 ml of concentrated sulfuric acid are added and the mixture is boiled under reflux for one hour. After removal of the methanol in vacuo, the residue is rendered alkaline with 33% strength sodium hydroxide solution and the mixture is extracted thoroughly by shaking with chloroform. The combined chloroform extracts are washed with a little water until neutral and dried over sodium sulfate and the solvent is distilled off in vacuo, whereupon 25.8 g of solid crude product (80.5% of theory) are obtained and are recrystallized from ethanol, with the addition of petroleum ether, at the boiling point.

Provenance & Evidence