反应详情

温度

0 °C

An alternative synthetic procedure is as follows. 75 g (435 mmol) of 2-chloro-5-nitroaniline was added to a solution of water (600 mL) and conc. sulfuric acid (60 mL) in a 3 L 3-neck flask equipped for mechanical stirring. The solution was cooled to 0° C. and a solution of sodium nitrite (34.2 g, 496 mmol) in water (130 mL) was added slowly. The mixture was stirred for ½ hr. and then a solution of potassium iodide (130 g, 783 mmol) in water (520 mL) was added dropwise over hr keeping the temperature below 15° C. The solution was stirred for 2 hr, then extracted with EtOAc (3×500 mL). The combined organic extracts were washed with sat. Na2S2O3 (2×500 mL), dried (Na2SO4), and concentrated. The crude iodide was dissolved in hot iPrOH (500 mL) and hexanes (200 mL) were added. The reaction was allowed to cool with stirring and the product was collected by suction filtration after stirring at 0° C. for 2 hr yielding 90 g (318 mmol, 73%) 2-chloro-5-nitro-iodobenzene as a light tan crystalline solid.

1. customequipped for mechanical stirring
2. customthe temperature below 15° C
3. stirringThe solution was stirred for 2 hr
4. extractionextracted with EtOAc (3×500 mL)
5. washThe combined organic extracts were washed with sat. Na2S2O3 (2×500 mL)
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated
8. dissolutionThe crude iodide was dissolved in hot iPrOH (500 mL)
9. additionhexanes (200 mL) were added
10. temperatureto cool
11. stirringwith stirring
12. filtrationthe product was collected by suction filtration
13. stirringafter stirring at 0° C. for 2 hr