反应详情

A solution of 5-methylpyrazine-2-carboxylic acid (15.0 g, 0.109 mol) in ethanol (70.0 mL) containing (1.5 g, 0.0079 mol) was heated to reflux for 4 h under argon atmosphere. The dark colored solution was cooled, added sod.bicarbonate (1.0 g) and concentrated under reduced pressure. The residue was partitioned between water (50 mL) and EtOAc (100 mL). The organic layer was washed with water (2×25 mL), dried (Na2SO4), and concentrated under reduced pressure to afford ethyl 5-methylpyrazine-2-carboxylate (12.05 g, 67%) as an orange colored liquid: 1H NMR (CD3OD/400 MHz) δ 9.1 (d. 1H, J=1.2 Hz), 8.62 (d, 1H, J=1.2 Hz), 4.45 (q, 2H, J=7.2 Hz), 2.63 (s, 3H), and 1,41 (t, 3H, J=7.2 Hz); ES MS m/z 167 (M+H). Step 2 Ethyl 5-(bromomethyl)pyrazine-2-carboxylate

1. temperaturewas heated
2. temperatureto reflux for 4 h under argon atmosphere
3. temperatureThe dark colored solution was cooled
4. additionadded sod
5. concentrationbicarbonate (1.0 g) and concentrated under reduced pressure
6. customThe residue was partitioned between water (50 mL) and EtOAc (100 mL)
7. washThe organic layer was washed with water (2×25 mL)
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated under reduced pressure