Hydrochloric Acid → 1H,3H-2,1,3-Benzothiadiazole 2,2-dioxide

Participants

Reaction Steps

A solution of orthophenylenediamine (20 g) and sulfamide (20.4 g) in diglyme (200 ml) was stirred at 160° C. for 2 hours, the reaction mixture was cooled to room temperature, water (200 g) was poured thereto, hydrochloric acid was added until pH 1, extracted with ethyl acetate, and washed with 1N hydrochloric acid. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give a reddish brown solid (14.2 g). Further recrystallization from ethanol-diethyl ether afforded the title compound as colorless crystals (13.2 g).

Provenance & Evidence