反应详情

4-Bromo-2-methoxy-phenylamine (2.02 g, 10 mmol) was added to a solution of p-toluensulphonic acid monohydrate (3.80 g, 20 mmol) in acetonitrile (30 mL). The mixture was cooled in an ice bath and treated with an solution of sodium nitrite (0.69 g, 10 mmol) and potassium iodide (4.15 g, 25 mmol) in water (7 mL) over 15 min maintaining the internal temperature below 10° C. After stirring at that temperature for 15 min and then for 0.5 h at room temperature, the reaction mixture was diluted with water and extracted with EtOAc (5×50 mL). The combined organic extracts were washed with 2M sodium thiosulfate (10 mL), brine (4×20 mL), water (20 mL), anhydrified over sodium sulphate, and evaporated to dryness affording a black oil that was purified by flash chromatography (petroleum ether/tert-butylmethyl ether 5/1) to yield the title compound (1.63 g, 52.2%).

1. temperatureThe mixture was cooled in an ice bath
2. temperaturemaintaining the internal temperature below 10° C
3. waitfor 0.5 h at room temperature
4. extractionextracted with EtOAc (5×50 mL)
5. washThe combined organic extracts were washed with 2M sodium thiosulfate (10 mL), brine (4×20 mL), water (20 mL)
6. customover sodium sulphate, and evaporated to dryness
7. customaffording a black oil that
8. customwas purified by flash chromatography (petroleum ether/tert-butylmethyl ether 5/1)