反应详情

A solution of tert-butyl 2-(6-methoxy-5-methyl-3-nitropyridin-2-yl)acetate (83.0 g, 294 mmol) in TFA (200 mL) was heated in a hot water bath for 1 h. The solution was concentrated in vacuo to give a brown oil. The oil was diluted with hexane and stirred. The resulting solid was collected by filtration and air dried to give 2-(6-methoxy-5-methyl-3-nitropyridin-2-yl)acetic acid (62.8 g, 94% yield) as a tan solid: 1H NMR (400 MHz, CDCl3) δ 8.70 (s br, 1H), 8.20 (s, 1H), 4.25 (s, 2H), 4.03 (s, 3H), 2.24 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 175.59, 163.80, 146.52, 139.16, 135.30, 121.53, 54.86, 42.88, 15.32. An analytical sample was recrystallized from hexane: mp 135-137° C. Anal. calcd. for C9H10N2O5: C, 47.79, H, 4.46, N, 12.39. Found: C, 47.65, H, 4.14, N, 12.30.

1. concentrationThe solution was concentrated in vacuo
2. customto give a brown oil
3. filtrationThe resulting solid was collected by filtration and air
4. customdried