反应详情

In a 250 ml 3-neck flask containing 50 ml of CHCl3 and 50 ml of glacial acetic acid, 9.5 grams (0.0558 mol) of ethyl thiophene-3-acetate was added, followed by 9.93 grams (0.0558 mol) of NBS. The mixture was stirred at room temperature for 12 hours. The mixture became clear yellow solution after 1 hour and then was cooled down to room temperature, and poured into 200 ml deionized (DI) water. The organic portion was washed again with 100 ml of DI-water, and then finally washed with 100 ml of 5% aqueous sodium bicarbonate solution. After having been dried over magnesium sulfate, the solvent was filtered and the product was concentrated under vacuum. The resulting residue was vacuum distilled at 95° C. under 1 mm mercury (Hg) yielding 12.3 grams of ethyl 2-bromothiophene-3-acetate (88% yield). 1H NMR (CDCl3): 1.26 (t, 3H), 3.60 (s, 2H), 4.16 (q, 2H), 6.93 (d, 1H), 7.22 (d, 1H).

1. additionwas added
2. customafter 1 hour
3. temperaturewas cooled down to room temperature
4. additionpoured into 200 ml
5. washThe organic portion was washed again with 100 ml of DI-water
6. washfinally washed with 100 ml of 5% aqueous sodium bicarbonate solution
7. dry with materialAfter having been dried over magnesium sulfate
8. filtrationthe solvent was filtered
9. concentrationthe product was concentrated under vacuum
10. distillationdistilled at 95° C. under 1 mm mercury (Hg)