反应详情

温度

5 °C

To a solution of 4-bromo-N1-methylbenzene-1,2-diamine (4.2 g, 21 mmol) in hydrochloric acid (2N, 50 ml) was added a solution of NaNO2 (1.52 g, 22 mmol) in water (5 ml) at 0° C. The resulting solution was stirred for 4 h at 0-10° C., adjusted to pH 8 with potassium hydroxide (3N), extracted with dichloromethane (2×200 ml), and the organic layers combined and concentrated under vacuum to give a residue, which was purified via silica gel chromatography (50% dichloromethane in petroleum ether) to afford 5-bromo-1-methyl-1H-benzo[d][1,2,3]triazole as a red solid (1.5 g, 31%).

1. extractionextracted with dichloromethane (2×200 ml)
2. concentrationconcentrated under vacuum
3. customto give a residue, which
4. customwas purified via silica gel chromatography (50% dichloromethane in petroleum ether)