反应详情

To a solution of fuming nitric acid (14.51 mL, 345 mmol), and sulfuric acid (14.45 ml, 271 mmol) was added 2-methylpyridin-4-ol (6.5 g, 59.6 mmol) portion wise at 25° C. and then stirred in oil bat set at 130° C. for 2 hours. The reaction was cooled to room temperature, poured over ice and the pH was adjusted to ˜7 using sodium carbonate. The mixture was cooled and a yellow precipitate formed which was then filtered and dried under vacuum for 2 hours in a rotovap set at 60° C. The solids were then slurried in methanol (100 mL) and sonicated 2×. The suspension was filtered and the solids discarded and the filtrate was concentrated under vacuum to give 2-methyl-3-nitropyridin-4-ol. 1H NMR (400 MHz, DMSO-d6) δ ppm 2.28 (3H, br. s.) 6.18-6.42 (1H, m) 7.71 (1H, d, J=7.58 Hz) 12.09 (1H, br. s.); MS [M+H] found 155.0.

1. additionpoured over ice
2. temperatureThe mixture was cooled
3. customa yellow precipitate formed which
4. filtrationwas then filtered
5. customdried under vacuum for 2 hours in a rotovap
6. customset at 60° C
7. customsonicated 2×
8. filtrationThe suspension was filtered
9. concentrationthe filtrate was concentrated under vacuum