反应详情

2-Amino-5-methylpyridine (2.16 g, 20.0 mmol) was added into 10 mL of conc H2SO4 in portions at room temperature with stirring. To the resulting solution was added 70% (HNO3 2.0 mL, 31.5 mmol) at room temperature dropwise with stirring. The mixture was then stirred at 55° C. (bath) for 2 h, cooled to room temperature and poured into crushed ice (about 100 g). The mixture was basified to pH 9 in ice-water bath by the addition of 40% aq. NaOH dropwise and the mixture was extracted with CHCl3 (5×25 mL). The CHCl3 extracts were combined, washed with brine (20 mL), dried (MgSO4), and rota-evaporated to dryness to give 770 mg (25% ) of 38 as a bright yellow powder, mp 175°-6° C. 1H NMR (CDCl3) δ2.291 (s, 3H), 6.556 (bs, 2H), 8.219 (s, 1H), 8.237 (s, 1H).

1. stirringwith stirring
2. stirringThe mixture was then stirred at 55° C. (bath) for 2 h
3. additionpoured
4. extractionthe mixture was extracted with CHCl3 (5×25 mL)
5. washwashed with brine (20 mL)
6. dry with materialdried (MgSO4)
7. customrota-evaporated to dryness