Dimethylformamide → 5-Bromo-2-chloro-3-nitropyridine

Beteiligte Stoffe

Reaktionsschritte

To a solution of 5-bromo-3-nitropyridin-2(1H)-one (4.62 g, 21.10 mmol) in POCl3 (46.2 ml) was added DMF (4.62 ml, 59.7 mmol) at room temperature. The mixture was refluxed for 2 hours, and then cooled to room temperature and concentrated in vacuo. The residue was treated with saturated aq. NaHCO3 and extracted with EtOAc. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by column chromatography on SiO2 (Hex:EtOAc=3:1) to give 5-bromo-2-chloro-3-nitropyridine (4.24 g, 85%) as a yellow solid. 1H-NMR (CDCl3, Varian 400 MHz) δ 8.37 (1H, d, J=2.4 Hz), 8.70 (1H, d, J=2.0 Hz).

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