Chlorosulfonic acid → Imidazo[1,2-a]pyridine-3-sulfonic acid

Participants

Reaction Steps

Chlorosulfonic acid (0.170 mL, 2.55 mmol) was dissolved in chloroform (1 mL) and this solution was added dropwise to imidazo[1,2-a]-pyridine (0.100 g, 0.85 mmol) in chloroform (4 mL) over 10 min. The reaction mixture was heated to reflux for 24 h, then allowed to cool to RT and concentrated to dryness under vacuum. The crude oily product was treated with diethyl ether (10 mL) and ethanol (5 mL) resulting in a white precipitate. The solid was collected by filtration, washed with EtOH and dried to yield imidazo[1,2-a]-pyridine-3-sulfonic acid (0.128 mg). MS (ESI−) for m/z 131 (M−H)−.

Provenance & Evidence