Cesium carbonate → Ethyl 4-{4-[(dimethylamino)carbonyl]phenoxy}-2-ethyl-1-benzofuran-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 2-ethyl-4-hydroxy-1-benzofuran-6-carboxylate (0.8 g, 3.4 mmol), 4-iodo-N,N-dimethylbenzamide (0.9 g, 3.3 mmol), Cs2CO3 (1.12 g, 3.4 mmol) and CuI (400 mg, 2.1 mmol) in pyridine (30 mL) was heated to 100° C. for 24 hours. TLC (petroleum ether/EtOAc 4:1) indicated the complete consumption of the phenol. The solvent was removed under reduced pressure. The residue was poured into water (20 mL) and extracted with EtOAc (30 mL×2). The combined organic layers were washed with brine (20 mL×2), dried over Na2SO4 and concentrated. The product was purified via silica gel column chromatography using petroleum ether/EtOAc (20:1 to 1:1) to afford the desired compound (400 mg, 30%) as a yellow solid. 1H NMR (400 MHz, CDCl3): δ 7.97 (s, 1H), 7.56 (s, 1H), 7.43 (d, 2H), 7.00 (d, 2H), 6.27 (s, 1H), 4.44-4.35 (q, 2H), 3.15-3.04 (d, 6H), 2.83-2.78 (q, 2H), 1.45-1.37 (t, 3H), 1.37-1.26 (t, 3H).

Provenance & Evidence