反应详情

2-Chloro-3-methyl-5-nitropyridine (3.2 g, 18.5 mmol; Maybridge Chemical Co.) was dissolved in a mechanically stirred solution of H2O/HOAc (60 mL, 5:1). Iron powder was added over a 5 h period, maintaining the temperature below 40° C., and stirring was continued until starting material had be consumed. The reaction mixture was filtered, and the filter cake was washed with EtOAc. The aqueous filtrate was extracted with EtOAc, and the combined organic fractions were washed with saturated NaHCO3 solution, dried (MgSO4) and concentrated. The residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2) to afford 5-amino-2-chloro-3-methylpyridine as an orange solid (2.34 g, 89%): MS (CI/NH3) m/z: 143 (M+H)+ ; NMR (DMSO-d6, 300 MHz) δ 2.17 (s, 3H), 5.40 (br s, 2H), 6.90 (d, J=2.2 Hz, 1H), 7.54 (d, J=2.2 Hz, 1H).

1. temperaturemaintaining the temperature below 40° C.
2. customhad be consumed
3. filtrationThe reaction mixture was filtered
4. washthe filter cake was washed with EtOAc
5. extractionThe aqueous filtrate was extracted with EtOAc
6. washthe combined organic fractions were washed with saturated NaHCO3 solution
7. dry with materialdried (MgSO4)
8. concentrationconcentrated
9. customThe residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2)