Carbon Dioxide → 1-(5-Acetoxy-6-bromohexyl)-3,7-dimethylxanthine

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Reaction Steps

To 1-(5,6-dihydroxyhexyl)-3,7-dimethylxanthine (1.0 g, 3.38mmol), prepared above, was added 30% hydrogen bromide-acetic acid (3.4 ml) over 30 sec and the resulting mixture was stirred until all of the solid had dissolved (2.5 hr). The solution was poured carefully over a mixture of sodium bicarbonate (12 gm) and ice water (50 ml). After carbon dioxide evolution had subsided, the mixture was extracted with dichloromethane (3×25 ml). The combined extracts were dried over magnesium sulfate and the solvent was evaporated under vacuum to give 1-(5-acetoxy-6-bromohexyl)-3,7-dimethylxanthine (1.3 g, 96% yield) as a viscous oil which was dissolved in methanol (5 ml). A 1M solution of sodium methoxide in methanol (3.9 ml) was added over 30 sec. After stirring for 20 min, the solution was treated with water (20 ml) and then extracted with dichloromethane (3×15 ml). The combined extracts were dried over magnesium sulfate and the solvents were evaporated under vacuum to give 1-(5,6-oxidohexyl)-3,7-dimethylxanthine (900 mg, 100% yield) as white crystals.

Provenance & Evidence