Dimethylformamide → 5-Bromo-1-methyl-3-nitropyridin-2(1H)-one

関与物質

反応手順

A 1-L round-bottomed flask equipped with a magnetic stirrer was purged with nitrogen and charged with 5-bromo-3-nitro-2-hydroxypyridine (24.0 g, 0.11 mol), anhydrous DMF (280 mL) and powdered potassium carbonate (−350 mesh, 33.4 g, 0.24 mol), and the suspension stirred for 15 min at ambient temperature. After this time methyl iodide (17.1 g, 0.124 mol) was added, and the mixture stirred at room temperature for 18 h. The reaction mixture was then diluted with water (750 mL) and extracted with ethyl acetate (3×1.0 L). The organic extracts were combined, washed with brine (500 mL) and dried over sodium sulfate. After removing the drying agent by filtration, the filtrate was evaporated to dryness under reduced pressure. The resulting residue was purified by flash chromatography on silica to afford an 85% yield (21.7 g) of 41 as a yellow solid: mp 122-123° C.; 1H NMR (300 MHz, CDCl3) δ 8.37 (d, 1H, J=2.7 Hz), 7.26 (s, 1H), 3.68 (s, 3H); MS (ESI+) m/z 234 (M+H).

情報源と証拠