Chlorosulfonic acid → HCID 22908976, compound

Participants

Reaction Steps

(E)-7-Methyl-1,3-dipropyl-8-styrylxanthine (WO92/06976) (500 mg, 1.42 mmol) was dissolved in chloroform (5 ml), and chlorosulfonic acid (0.28 ml, 4.26 mmol) was added dropwise thereto at 0° C. The resulting solution was heated under reflux for 3 hours and then poured into 20 ml of ice-water. The chloroform layer was separated and the aqueous layer was extracted 5 times with tetrahydrofuran. The combined organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give 240 mg (yield 39%) of Compound 31 as a pale yellow powder.

Provenance & Evidence