2-Chloro-3-methyl-5-nitropyridine → 6-Chloro-5-methylpyridin-3-amine

Beteiligte Stoffe

Reaktionsschritte

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).

Herkunft & Nachweise