Potassium Iodide → 4-bromo-1-(2,2-dimethylpropyl)-5-iodo-1H-benzotriazole

Participants

Reaction Conditions

Reaction Steps

To a solution of para-toluenesulfonic acid monohydrate (510 mg, 2.68 mmol) in acetonitrile (3.5 mL), was added 4-bromo-1-(2,2-dimethylpropyl)-1H-1,2,3-benzotriazol-5-amine (253 mg, 0.893 mmol). The resulting suspension was cooled to 10-15° C. and treated with an aqueous solution of sodium nitrite (537 μl, 1.787 mmol) and potassium iodide (536 μl, 2.23 mmol). The mixture was stirred for 10 minutes at 0° C. and then warmed to ambient temperature. The mixture was diluted with water and treated with sodium bicarbonate (1 M, aqueous) until the mixture was adjusted to pH 9-10, which was followed by treatment of a 3 M aqueous solution of Na2S2O3 (6 mL). The solid was collected by filtration and washed with cold diethyl ether and hexane. The residue was purified via silica gel chromatography (ethyl acetate/hexane gradient), providing the titled compound: 1H NMR (500 MHz, CDCl3) 7.86 (d, 1H, J=8.7 Hz), 7.25 (d, 1H, J=9.0 Hz), 4.36 (s, 2H), 1.04 (s, 9H) ppm. LRMS m/z (M+H) 393.8 and 395.8 found, 393.9 and 395.9 required.

Provenance & Evidence