Hydrochloric Acid → HCID 10621185, compound

Participants

Reaction Conditions

Reaction Steps

5.0 g of methyl 2-hydroxy-4-methylsulfonylamino-5-phenoxyphenyl ketone was suspended in 85 ml of ethanol. Thereto was added 4.5 ml of diethyl oxalate. Further, 3.1 g of sodium hydride (purity: 60%) was added thereto in portions in 10 minutes. The mixture was refluxed for 1.5 hours. The reaction mixture was introduced into 300 ml of ice water. The resulting mixture was adjusted to pH 2 with 4N hydrochloric acid. The resulting crystal was collected by filtration and then suspended in 50 ml of acetic acid. 1 ml of concentrated hydrochloric acid was added thereto. The mixture was stirred for 10 minutes at 80° C. After the completion of the reaction, 200 ml of water and 200 ml of ethyl acetate were 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 recrystallized from a mixed solvent of ethyl acetate and diisopropyl ether to obtain 3.5 g (yield: 56%) of 2-ethoxycarbonyl-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one having a melting point of 155°-156° C.

Provenance & Evidence