反应详情

A solution of 5-acetylthiophene-2-carboxylic acid (17.0 g, 100 mmol) in ethanol (500 mL) was treated with a concentrated H2SO4 solution (10 mL) and heated at reflux for 3 days after which time the reaction was evaporated to approximately ¼ volume and partitioned between EtOAc (300 mL) and water (100 mL). The organic portion was then further washed with a saturated aqueous solution of NaHCO3 (2×100 mL) followed by a brine solution (100 mL), then dried over MgSO4, filtered, and evaporated in vacuo to afford product as light brown colored solid (25.0 g, 84%). 1H NMR (CDCl3) 1.39 (t, J=7.0, 3H), 2.59 (s, 3H), 4.38 (q, J=7.3, 2H), 7.64 (d, J=4.0, 1H), 7.76 (d, J=4.0, 1H). 13C NMR 14.3, 27.1, 61.9, 131.8, 133.3, 140.3, 148., 161.7, 190.9. LC/MS 5.47 min, [M+1]+ 199.

1. temperatureheated
2. temperatureat reflux for 3 days after which time the reaction
3. customwas evaporated to approximately ¼ volume
4. custompartitioned between EtOAc (300 mL) and water (100 mL)
5. washThe organic portion was then further washed with a saturated aqueous solution of NaHCO3 (2×100 mL)
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. customevaporated in vacuo