反应详情

温度

90 °C

2-chloro-6-methylpyridine 1-oxide (60 g, 0.42 mol) was dissolved in 98% sulfuric acid (60 mL) at 0° C., then a solution of HNO3 (50 mL) and H2SO4 (50 mL) was added dropwise at the same temperature. After the addition was complete, the reaction was stirred at 90° C. for 3 h. The reaction was poured into ice-water, neutralized with NaHCO3, and then extracted with ethyl acetate (3×500 mL). The combined organic layers were washed with brine (500 mL), dried over magnesium sulfate, filtered and concentrated to afford 2-chloro-6-methyl-4-nitropyridine 1-oxide which was used without further purification. 1H NMR (300 MHz, CDCl3) δ 8.27 (d, J=2.7 Hz, 1H), 8.07 (d, J=0.6 Hz, 1H), 2.62 (s, 3H). LRMS calc'd for (C6H6ClNO) [M+H]+, 189; found 189.

1. additionAfter the addition
2. extractionextracted with ethyl acetate (3×500 mL)
3. washThe combined organic layers were washed with brine (500 mL)
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated