反应详情

2-Chloro-3-methyl-5-nitropyridine (139 g, 0.806 mol) from the above procedure was divided into two portions and placed in two 2-L round bottom flasks with methanol (500 mL). The solutions were cooled in dry ice/isopropanol baths as solid sodium methoxide (26.5 g, 0.467 mol) was added portion-wise to each flask so that the temperature was remained below 20° C. When the additions were complete, the resulting mixtures were heated to reflux for 1 h. The mixtures were cooled and diluted with ice water (500 mL) to give white precipitates, which were collected by filtration. The combined filtrates were washed with water and air dried to give 2-methoxy-3-methyl-5-nitropyridine (127 g, 97% yield) as a white solid: 1H NMR (400 MHz, CDCl3) δ 8.91 (d, J=2.0 Hz, 1H), 8.16 (s, 1H), 4.06 (s, 3H), 2.25 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 165.83, 141.91, 139.37, 132.92, 121.77, 54.83, 15.84. An analytical sample was recrystallized from hexane to give white needles, mp 95-96.5° C. Anal. calcd. for C7H8N2O3: C, 50.00; H, 4.79; N, 16.66. Found: C, 49.73; H, 5.02; N, 16.48.

1. additionwas added portion-wise to each flask so that the temperature
2. customwas remained below 20° C
3. temperaturethe resulting mixtures were heated
4. temperatureto reflux for 1 h
5. temperatureThe mixtures were cooled
6. customto give white precipitates, which
7. filtrationwere collected by filtration
8. washThe combined filtrates were washed with water and air
9. customdried