反应详情

A solution of 2-aminonicotinic acid (2.0 g, 14.4 mmol) in anhydrous EtOH (70 mL) and concentrated sulfuric acid (14 mL) was heated to reflux for 16 h. The solution was concentrated under reduced pressure, neutralized with saturated aqueous Na2CO3 (50 mL) and extracted with CH2Cl2 (3×50 mL). The combined organic phases were dried (MgSO4), filtered and concentrated to give 2-aminonicotinic acid ethyl ester as a yellow solid (1.74 g, 74%). 1H NMR (CDCl3) δ 1.40 (t, 3H, J=6.0 Hz), 4.34 (q, 2H, J=7.0 Hz), 6.41 (br s, 2H (NH2)), 6.63 (m, 1H), 8.14 (d, 1H, J=7.8 Hz), 8.22 (s, 1H).

1. temperatureto reflux for 16 h
2. concentrationThe solution was concentrated under reduced pressure
3. extractionextracted with CH2Cl2 (3×50 mL)
4. dry with materialThe combined organic phases were dried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated