反应详情

2-Chloro-4-fluoro-6-nitroaniline was prepared using an adaptation of the method of Mitchell, et al. (Mitchell, R. H. et al., J. Org. Chem. 44: 4733 (1979)). To a solution of 4-fluoro-2-nitroaniline (500 mg, 3.2 mmol) in dry DMF (10 mL) under N2 was added dropwise a solution of N-chlorosuccinimide (426 mg, 3.2 mmol) in dry DMF (16 mL). The reaction was allowed to stir overnight. The solution was then poured into 100 mL H2O and the resulting cloudy suspension extracted with 4×25 mL ethyl acetate. The combined organic phases were washed with 4×25 mL H2O and 25 mL saturated NaCl solution and dried (MgSO4). The MgSO4 was vacuum filtered and the solvent rotary evaporated to yield a brown crystalline solid which was purified further by flash chromatography (2:1 hexanes:ethyl acetate) to yield 424 mg of an orange crystalline solid (69.5%) 1H NMR (CDCl3) δ 6.46 (br s, 2H, NH2), 7.42 (dd, JH5-3 =3 Hz, JH3-F =7.2 Hz, H-4), 7.85 (dd, JH5-3 =3 Hz, JH5-F =8.7 Hz, H-5)

1. extractionthe resulting cloudy suspension extracted with 4×25 mL ethyl acetate
2. washThe combined organic phases were washed with 4×25 mL H2O and 25 mL saturated NaCl solution
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. customthe solvent rotary evaporated
6. customto yield a brown crystalline solid which
7. customwas purified further by flash chromatography (2:1 hexanes:ethyl acetate)