Potassium Iodide → 7-Bromo-5-iodo-benzo[d]isothiazole

Participants

Reaction Conditions

Reaction Steps

To a solution of p-toluenesulfonic acid monohydrate (1.36 g, 7.2 mmol) in acetonitrile (8.5 mL) was added 7-bromo-benzo[d]isothiazol-5-ylamine (400 mg, 1.74 mmol). The resulting suspension was cooled to 10 to 15° C. and a solution of sodium nitrite (331 mg, 4.8 mmol) and potassium iodide (996 mg, 6 mmol) in water (1.5 mL) was added gradually. The reaction mixture was stirred for 10 min and then allowed to come to RT and stirred for 16 h. The reaction mixture was treated with water (5 mL) and aqueous 1.0 N sodium bicarbonate solution (15 mL), and aqueous 2.0 N sodium thiosulfate solution (10 mL). The precipitate was collected by filtration and the purified by column chromatography (25% ethyl acetate:hexanes) to afford 300 mg (50%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 8.9 (s, 1H), 8.37 (d, J=1.2 Hz, 1H), 7.91 (d, J=1.5 Hz, 1H).

Provenance & Evidence