Pyridine → 2-Chloro-5-methyl-3-nitropyridine

Beteiligte Stoffe

Reaktionsschritte

A solution of 5-methyl-3-nitro-1H-pyridone (3.1 g, 20 mmol) in 50 mL chlorobenzene was treated with pyridine (0.47 g, 6.0 mmol) and phosphorus oxychloride (4.7 g, 30.8 mmol). The mixture was refluxed for 1 h. Upon cooling it was treated with sodium carbonate aq. followed by extraction with CH2Cl2. The organic phase was dried over Mg2SO4 and filtered. The solvent was evaporated in vacuo to give 2.6 g of the titled compound which was further purified by flash chromatography on silica gel (PE:EtOAc, 8:2, v/v). 1H-NMR (CDCl3) δ: 2.45 (s, 3H, CH3), 8.44 (d, 1H, J=2.0 Hz, Py-H), 8.58 (d, 1H, J=2.0 Hz, Py-H); MS (ESI+) m/z 173.0209 [M+H]+, C6H5ClN2O2 requires 172.0040.

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