反应详情

A 50-mL single-neck round-bottomed flask equipped with a mechanical stirrer was charged with 3-bromo-1-methyl-5-(2-methyl-3-nitrophenyl)pyridin-2-one (11) (0.70 g, 2.17 mmol), ethanol (15 mL), iron powder (−325 mesh, 1.20 g, 21.7 mmol), 2N hydrochloric acid (1.09 mL, 2.17 mmol) and stirred at reflux for 4 h. After this time the reaction was cooled to room temperature and solid potassium carbonate (0.738 g, 5.35 mmol) was added. The suspension was stirred for 0.5 h and then filtered through a pad of Celite 521. The filter cake was washed with ethanol (3×15 mL) and the combined filtrates were concentrated to a constant weight under reduced pressure to afford 0.71 g (88%) of 5-(3-amino-2-methylphenyl)-3-bromo-1-methylpyridin-2-one (12) as a yellow oil: 1H NMR (300 MHz, CDCl3) 7.75 (dd, 1H, J=2.1 Hz), 7.23 (d, 1H, J=2.1 Hz), 7.05 (t, 1H, J=7.8 Hz), 6.72 (d, 1H, J=7.8 Hz), 6.60 (d, 1H, J=7.2 Hz), 3.75 (br s, 2H), 3.66 (s, 3H), 2.07 (s, 3H); MS (ESI+) m/z 293 (M+H).

1. customA 50-mL single-neck round-bottomed flask equipped with a mechanical stirrer
2. temperatureat reflux for 4 h
3. stirringThe suspension was stirred for 0.5 h
4. filtrationfiltered through a pad of Celite 521
5. washThe filter cake was washed with ethanol (3×15 mL)
6. concentrationthe combined filtrates were concentrated to a constant weight under reduced pressure