反应详情

温度

78 °C

The reaction is carried out, under nitrogen, in a 1 L×4 neck flask equipped with a mechanical stirrer, water condenser (with gas inlet), and a thermocouple. The reactor is charged with 5-methylpyrazinecarboxylic acid (100 g), ethanol (300 g) and sulfuric acid (2 g). The contents are refluxed for eight hours at 78° C. The reaction mixture is cooled to ambient temperature and sodium bicarbonate (4 g) is added. About 75% of the solvent is removed under reduced pressure and the resulting suspension is allowed to stand overnight. The solids are filtered and washed with cold methanol (2×80 g). Drying under oven (25 inches of Hg) yielded 101.25 g (84%) of 5-methyl-2-pyrazinecarboxylic acid, ethyl ester.

1. customequipped with a mechanical stirrer, water condenser (with gas inlet)
2. temperatureThe reaction mixture is cooled to ambient temperature
3. customAbout 75% of the solvent is removed under reduced pressure
4. filtrationThe solids are filtered
5. washwashed with cold methanol (2×80 g)
6. customDrying under oven (25 inches of Hg)