反应详情

To a stirred solution of 3-methylthiophene-2-carboxylic acid (1.84 g, 12.9 mmol) in ethanol (20 mL) was added thionyl chloride (0.94 mL, 12.9 mmol). The resulting reaction mixture was stirred at reflux for 20 h, and then allowed to cool to ambient temperature and concentrated in vacuo. The residue was taken up in ethyl acetate (200 mL) and washed with saturated aqueous sodium bicarbonate (2×100 mL). The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to afford ethyl 3-methylthiophene-2-carboxylate as light yellow liquid (1.89 g, 86%): 1H NMR (300 MHz, CDCl3) δ 7.37 (d, J=5.0 Hz, 1H), 6.90 (d, J=5.0 Hz, 1H), 4.32 (q, J=7.1 Hz, 2H), 2.55 (s, 3H), 1.37 (t, J=7.1 Hz, 3H).

1. customThe resulting reaction mixture
2. temperatureat reflux for 20 h
3. concentrationconcentrated in vacuo
4. washwashed with saturated aqueous sodium bicarbonate (2×100 mL)
5. dry with materialThe organic layer was dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo