Acetic Anhydride → Ethyl 4-(acetyloxy)-2-ethyl-1-benzofuran-6-carboxylate

Participants

Reaction Steps

A mixture of (ethoxycarbonyl)-4-(5-ethyl-2-furyl)but-3-enoic acid (45.4 g, 0.18 mol) and sodium acetate (59.0, 0.72 mol) in acetic anhydride (450 mL) was heated to reflux for 5 hours. TLC (petroleum ether/EtOAc 4:1) indicated complete consumption of the starting material. The reaction mixture was concentrated and the residue was poured into 15% aq. Na2CO3 (500 mL), and extracted with EtOAc (500 mL×3). The combined organic layers was washed with brine (200 mL), dried over Na2SO4, and concentrated. The product was purified via silica gel column chromatography using petroleum ether/EtOAc (70:1) to afford the desired compound (13.0 g, 28%) as a yellow solid.

Provenance & Evidence