反应详情

A solution of 2-pyrazinecarboxylic acid (2.00 g, 16.1 mmol) and H2SO4 (catalytic) in MeOH (50 mL) was heated at reflux for 45 minutes, then concentrated in vacuo. The residue was partitioned between EtOAc (40 mL) and saturated NaHCO3(aq) (20 mL). The organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL), then dried (MgSO4) and concentrated in vacuo to give colourless crystals (1.32 g, 59%). 1H NMR (CDCl3) □ 4.04 (s, 3H), 8.72 (dd, 11H, J=2.4, 1.2 Hz), 8.77 (d, 1H, J=2.4 Hz), 9.32 (d, 1H, J=1.2 Hz).

1. temperatureat reflux for 45 minutes
2. concentrationconcentrated in vacuo
3. customThe residue was partitioned between EtOAc (40 mL) and saturated NaHCO3(aq) (20 mL)
4. washThe organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo