Acetic Acid → 1-(8-Acetoxy-9-bromononyl)-3,7-dimethylxanthine

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Reaction Steps

A mixture of 1-(8,9-dihydroxynonyl)-3,7-dimethylxanthine, prepared above, and 30% hydrogen bromide in acetic acid (0.8 ml, 3.90 mmol) was stirred for 90 minutes. The solution was poured into a mixture of water (10 ml), sodium bicarbonate (1.35 g, and dichloromethane (10 ml). After 10 minutes of vigorous stirring, the layers were separated and the aqueous portion was extracted with three 15 ml aliquots of dichloromethane. The combined organic phases were dried over sodium sulfate and the solvent was evaporated under vacuum, leaving 550 mg of a yellow oil, 1-(8-acetoxy-9-bromononyl)-3,7-dimethylxanthine (96% yield). Without further purification, the oil was dissolved in methanol (5 ml), to which a 1 M solution of sodium methoxide in methanol (4.1 ml, 4.1 mmol) was added. After 30 minutes, the reaction mixture was poured into water (30 ml) was extracted with three 40 ml aliquots of dichloromethane. The combined organic layers were dried over sodium sulfate. Evaporating the solvents under vacuum left a solid residue. Recrystallization in dichloromethane-petroleum ether yielded 380 mg of 1-(8,9-oxidononyl)-3,7-dimethylxanthine (91% yield).

Provenance & Evidence