Cesium carbonate → 4-(3-Fluoro-4-methanesulfonyl-phenoxy)-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid methyl ester

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Reaction Conditions

Reaction Steps

A mixture of 2,4-difluorophenyl methyl sulfone (865 mg, 4.50 mmol), 4-hydroxy-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid methyl ester (3e) (1.00 g, 4.50 mmol), and Cs2CO3 (2.93 g, 9.00 mmol) in DMF (2 mL) was heated to 80° C. for 2.5 h, cooled to room temperature, quenched with H2O and extracted with 3×EtOAc. The organic layers were washed with 2×H2O, dried over Na2SO4 and concentrated. The residue was purified by Biotage column chromatography with 15%-40% EtOAc in hexanes to give a white solid (1.20 g, 68% yield). 1H NMR (400 MHz, CDCl3) δ 7.82-7.95 (m, 1 H) 7.21-7.34 (m, 2 H) 6.72-6.88 (m, 2 H) 3.90 (s, 3 H) 3.22 (s, 3 H) 2.90 (s, 2 H) 1.48 (s, 6 H); LCMS for C19H19FO6S m/z 395.00 (M+H)+.

Provenance & Evidence