Dimethyl Sulfoxide → 1-(6-Oxohexyl)-3,7-dimethylxanthine

Participants

Reaction Steps

Dimethyl sulfoxide (156 mL, 172 mg, 2.2 mmol) was slowly added to a solution of oxalyl chloride (103 mL, 150 mg, 1.2 mmol) at -78° C. A solution of 1-(6-hydroxyhexyl)-3,7-dimethylxanthine (300 mg, 1.1 mmol) in methylene chloride (5 mL) was added, followed by 15 minutes of stirring. The cold bath was removed after addition of triethylamine (765 mL, 555 mg, 5.5 mmol). The reaction was added at room temperature to 20 mL water and extracted with methylene chloride (3×50 mL). The organic layers were combined and washed with 1% hydrogen chloride (20 mL), saturated sodium bicarbonate (20 mL), and brine (20 mL) and then dried over sodium sulfate. Evaporation of solvent and recrystallization of the residue in chloroform/petroleum ether yields 267 mg 1-(6-oxohexyl)-3,7-dimethylxanthine (87% yield).

Provenance & Evidence