Hydrogen Bromide → HCID 23295947, compound

Participants

Reaction Steps

1-(4,5-Dihydroxypentyl)-3,7-dimethylxanthine (2.13 g, 7.6 mmol) was stirred with hydrogen bromide (4.74 mL, 6.15 g of a 30% solution in acetic acid, 22.8 mrnol) for 90 minutes. The mixture was then added to a flask containing 50 mL aqueous sodium bicarbonate solution and 50 mL dichloromethane. After 10 minutes of vigorous stirring, the layers were separated and the aqueous portion washed with dichloromethane (3×50 mL). The organic portions were combined, dried over magnesium sulfate, and the solvent evaporated to yield 3.4 g (96%) 1-(4-acetoxy-5-bromopentyl)-3,7-dimethylxanthine as a yellow oil. Without further purification, the oil was taken up in methanol (25 mL) and treated with a solution of sodium methoxide (prepared from 0.2 g, 8.7 mmol sodium, and 25 mL methanol). After 30 minutes most of the solvent was removed under reduced pressure and the residue extracted with dichloromethane (3×50 mL). The organic portions were combined and dried over magnesium sulfate to obtain an off-white solid purified by column chromatography over silica gel using ethyl acetate/(15%) acetone eluant to yield 1.0 g (50% yield) of 1-(4,5-Oxipentyl)-3,7-dimethylxanthine.

Provenance & Evidence