2,5-Dichlorothiophene → 2,5-Dichlorothiophene-3-sulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

A 96.8-g (0.632 mol) sample of 2,5-dichlorothiophene was added dropwise to a cooled (dry ice/acetone bath, about -10° to -15° C.) and stirred solution of 163 g (1.39 mol) of chlorosulfonic acid. After the addition was completed, the reaction mixture was stirred at 50° C for 2 hours, cooled, and then poured into 200 g of ice. The aqueous reaction mixture was extracted with methylene chloride. The methylene chloride extract was washed with saturated aqueous sodium bicarbonate solution, washed with water, dried over magnesium sulfate, and evaporated to give 87 g of 2,5-dichloro-3-thienylsulfonyl chloride.

Provenance & Evidence