Chlorosulfonic acid → 2-Amino-5-bromopyridine-3-sulfonyl chloride

Participants

Reaction Steps

To a cooled (0° C.) solution of chlorosulfonic acid (58 mL) under vigorous stirring was added 5-bromo-2-pyridinamine (86.7 mmol) portion wise. The reaction mixture was then heated at reflux for 3 h. Upon cooling to room temperature, the reaction mixture was poured over ice (100 g) with vigorous stirring. The resulting yellow precipitate was collected by suction filtration, washed with cold water and petroleum ether to provide 2-amino-5-bromopyridine-3-sulfonyl chloride (18 g, 77% yield) as an orange-yellow solid.

Provenance & Evidence