反应详情

温度

0 °C

A solution of sodium nitrite (7.6 g, 110 mmol) in water (30 mL) was added dropwise over 15 min to a stirred suspension of 2-fluoro-4-methyl-5-nitroaniline (17 g, 100 mmol) in hydrobromic acid, (48%, 150 mL) and water (30 mL) at 0° C. The mixture was stirred at 0° C. for 15 min then added portionwise over 10 min to a stirred suspension of copper(I)bromide (16.5 g, 112 mmol) in hydrobromic acid (48%, 50 mL) and water (90 mL) at 0° C. The mixture was stirred at 0° C. for 30 min then warmed to room temperature and stirred for 3 h. The mixture was poured onto ice-water (500 mL) and extracted with ethyl acetate (3×). The combined organic extracts were washed with saturated aqueous sodium bicarbonate solution, dried (magnesium sulfate), concentrated in vacuo and purified by column chromatography [SiO2; heptane-ethyl acetate (19:1)] to give the product (11.8 g, 50%) as an off-white solid: IR νmax (nujol)/cm−1 2925, 2855, 1571, 1523, 1478, 1349, 1264, 1103, 895, 671 and 589; NMR δH (400 MHz, CDCl3) 8.27 (1H, d, J 6.5), 7.10 (1H, d, J 9.1), 2.60 (3H, s).

1. stirringThe mixture was stirred at 0° C. for 30 min
2. temperaturethen warmed to room temperature
3. stirringstirred for 3 h
4. additionThe mixture was poured onto ice-water (500 mL)
5. extractionextracted with ethyl acetate (3×)
6. washThe combined organic extracts were washed with saturated aqueous sodium bicarbonate solution
7. dry with materialdried (magnesium sulfate)
8. concentrationconcentrated in vacuo
9. custompurified by column chromatography [SiO2; heptane-ethyl acetate (19:1)]