Ethyl Acetate → ethyl (3S)-3-[N-(2-chloro-4-fluorophenyl)sulfamoyl]-3,6-dihydro-2H-pyran-4-carboxylate

Participants

Reaction Steps

To a solution (200 mL) of ethyl (3S)-3-{[(2-chloro-4-fluorophenyl)amino]sulfanyl}-3,6-dihydro-2H-pyran-4-carboxylate (12.3 g) in ethyl acetate was added meta-chloroperbenzoic acid (24.5 g) at 0° C. After stirring at room temperature for 2 hr, the mixture was again cooled to 0° C., and 5% aqueous sodium sulfite solution (200 mL) and saturated aqueous sodium hydrogen carbonate solution (200 mL) were added dropwise. After extraction with ethyl acetate (200 mL×2), the extract was washed with saturated aqueous sodium hydrogen carbonate solution (200 mL) and water (200 mL), and dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was subjected to silica gel column chromatography (hexane/ethyl acetate=2:1) to give the title compound as a crude product (13.8 g). This product was crystallized from ethyl acetate/diisopropyl ether/hexane (115 mL, 5:100:10) to give the title compound (12.0 g, 90%).

Provenance & Evidence