Cesium carbonate → 5-(4-Methanesulfonyl-phenoxy)-2-methyl-benzofuran-7-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Cs2CO3 (2.36 g, 7.24 mmol) and 4-fluorophenyl methyl sulfone (631 mg, 3.62 mmol) were added to a solution of 5-hydroxy-2-methyl-benzofuran-7-carboxylic acid methyl ester (4d) (746 mg, 3.62 mmol) in DMF (5 mL). The mixture was heated to 120° C. overnight and then cooled to RT. The mixture was then quenched with H2O (80 mL) and extracted with EtOAc 92×100 ml). The combined organic layers were dried over MgSO4 and concentrated. The residue was purified by flash column chromatograph eluting with 4% CH3OH/CH2Cl2 to afford brown color oil (1.2 g, 92%). 1H NMR (400 MHz, CDCl3) δ 8.02 (s, 2 H) 7.86-7.90 (m, 1 H) 7.58 (d, J=2.53 Hz, 1 H) 7.38 (d, J=2.53 Hz, 1 H) 7.05 (d, J=8.84 Hz, 1 H) 6.44 (s, 1H) 3.99 (s, 3 H) 3.05 (s, 3 H) 2.56 (s, 3 H); LCMS for C18H16O6S m/z 361.00 (M+H)+.

Provenance & Evidence