Ethyl Acetate → HCID 10808954, compound

Participants

Reaction Steps

30 g of polyphosphoric acid was added to 1.0 g of trans-3-[4-(2,4-difluorophenoxy)-3-methylsulfonylaminophenoxylacrylic acid. The mixture was stirred for 1 hour at 55°-65° C. The reaction mixture was introduced into 200 ml of ice water. 50 ml of ethyl acetate was added thereto. The organic layer was separated, washed with water and a saturated aqueous sodium chloride solution in this order, and dried with anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. The residue was purified by a column chromatography (eluant: a 5 : 1 mixture of toluene and ethyl acetate) to obtain 0.4 g (yield: 42.0%) of 6-(2,4-difluorophenoxy)-7-methylsulfonylamino-4H-1-benzopyran-4-one. Melting point: 182.2°-182.8° C. (recrystallized from ethyl acetate)

Provenance & Evidence