p-Toluenesulfonic acid → Ethyl 11-bromoundecanoate

This example is a method of synthesis for inventive compound no. 3556. A solution of 11-bromoundecanoic acid (available from Aldrich, 5.70 g, 22 mmol) and p-toluenesulfonic acid (0.1 g) in absolute ethanol (100 ml) was refluxed for 3 hours. Saturated aqueous sodium bicarbonate solution (40 ml) was added and the reaction mixture was extracted with dichloromethane (3×70 ml). The combined extracts were washed with water (50 ml) and saturated aqueous salt solution (50 ml), and then the solvent was evaporated to a colorless oil. Ethyl 11-bromoundecanoate (5.92 g, 94% yield) was collected during distillation (2 mm) at 135° C. A solution of the bromoester (5.92 g, 20 mmol) and 1-sodiotheobromine (4.08 g, 20 mmol) in dimethylsulfoxide (80 ml) was stirred for 18 hours at ambient temperature. The mixture was added to water (100 ml) and dichloromethane (100 ml). The aqueous layer was extracted with dichloromethane (2×80 ml). The combined organic layers were washed with water (80 ml) and saturated aqueous salt solution (80 ml), dried over magnesium sulfate, and evaporated under vacuum to a white solid. The residue was recrystallized in dichloromethane/ether/hexane, yielding 4.95 g of 1-(ethyl 11-yl-undecanoate)-3,7-dimethylxanthine (62% yield).

1. customa method of synthesis for inventive compound no
2. extractionthe reaction mixture was extracted with dichloromethane (3×70 ml)
3. washThe combined extracts were washed with water (50 ml) and saturated aqueous salt solution (50 ml)
4. customthe solvent was evaporated to a colorless oil

ORD record

ord-178e5ec34ffe4c35bb6158ead0407534

Source dataset

uspto-grants-1998_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05807861