Chlorosulfonic acid → HCID 22909004, compound

Participants

Reaction Steps

(E)-8-(3,4-Dimethoxystyryl)-7-methyl-1,3-dipropylxanthine (WO92/06976) (2.41 g, 5.84 mmol) was dissolved in thionyl chloride (11 ml), and chlorosulfonic acid (1.17 ml, 17.53 mmol) was added dropwise thereto at 0° C. The resulting solution was stirred at room temperature for 30 minutes and then poured into ice-water cautiously. The precipitated crystals were collected by filtration, washed with water, and dried under reduced pressure to give 2.77 g (yield 93%) of Compound 1 as a yellow powder.

Provenance & Evidence