Under ice bath conditions, 3-bromobenzenesulfonyl chloride (4.073 g, 15.94 mmol) was dissolved in dichloromethane (67 mL) and 25% ammonia solution (3.7 mL, 57.15 mmol) was slowly added. The reaction mixture was stirred at ice bath temperature for 0.5 hr, then brought to room temperature and continued stirring for 6 hr. Upon completion of the reaction, the precipitated solid was collected by filtration, washed with water and dried under vacuum in the presence of phosphorus pentoxide to afford 3-bromobenzenesulfonamide (3.270 g, 87% yield) in white crystalline form. NMR hydrogen spectrum (DMSO-d6) δ: 7.97 (t, J = 1.9 Hz, 1H), 7.84-7.80 (m, 2H), 7.54 (t, J = 7.9 Hz, 1H), 7.50 (bs, 2H). Liquid chromatography-mass spectrometry (ESI) m/z: 235.98 [M-H]-.
