Sulfuric Acid → Ethyl (5-bromobenzofuran)-2-carboxylate

Participants

Reaction Steps

The compound was prepared according to a literature procedure. (Yoo et al., Bioorg. Med. Chem. 5:445, 1997). To ethyl (4-bromo-2-formylphenoxy)acetate (Example 1, 14.3 g, 49.7 mmol) was added, under Ar, 115 mL absolute EtOH. To this mixture was added 5.28 g (77.7 mmol) sodium ethoxide and the reaction allowed to reflux overnight. Sulfuric acid (conc., 2 mL) was then added, and the reaction allowed to reflux an additional 2 hours. The mixture was then cooled to rt, 50 mL was added and the pH adjusted to neutrality with 1 N NaOH. The mixture was then extracted with 150 mL EtOAc, and the combined organic phase was washed with brine (2×150 mL), dried over Na2SO4, and filtered. The solvent was removed in vacuo. Purification by Biotage® separation using 5% EtOAc/hexanes provided 3.62 g (27%) of the desired compound. 1H-NMR (CDCl3, 67 ): 1.43 (t, 3H), 4.45 (q, 2H), 7.46-7.57 (m, 3H), 7.82 (s, 1H); LRMS (GC/MS/EI) 268 [M]+.

Provenance & Evidence