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

Dimethyl sulfoxide (156 μl, 172 mg, 2.2 mmol) was slowly added to a solution of oxalyl chloride (103 μl, 150 mg, 1.2 mmol) in dichloromethane at -78° C. A solution of 1-(6-hydroxyhexyl)-3,7-dimethylxanthine (300 mg, 1.1 mmol), prepared in the previous step, in dichloromethane (5 ml) was added to this solution and the resulting reaction mixture stirred for 15 minutes. The cold bath was removed after addition of triethylamine (765 μl, 555 mg, 5.5 mmol). The reaction was added at ambient temperature to 20 ml water and extracted with three 50 ml aliquots of methylene chloride. The combined organic layers were washed with 1% aqueous hydrogen chloride (20 ml), saturated aqueous sodium bicarbonate (20 ml), and saturated aqueous salt solution (20 ml), and then dried over sodium sulfate. Evaporating the solvents and recrystallizing a residue in chloroform/petroleum ether produced 267 mg of 1-(6-oxohexyl)-3,7-dimethylxanthine (87% yield).

1. additionwas added to this solution
2. customthe resulting reaction mixture
3. customThe cold bath was removed
4. extractionextracted with three 50 ml aliquots of methylene chloride
5. washThe combined organic layers were washed with 1% aqueous hydrogen chloride (20 ml), saturated aqueous sodium bicarbonate (20 ml), and saturated aqueous salt solution (20 ml)
6. dry with materialdried over sodium sulfate
7. customEvaporating the solvents
8. customrecrystallizing a residue in chloroform/petroleum ether

ORD record

ord-c4c5fabf0dad436c983a42c8a75b2f9f

Source dataset

uspto-grants-2000_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06103730