Diisopropyl Ether → HCID 22168218, compound

Participants

Reaction Steps

2.0 g of methyl 5-acetoxy-2-hydroxy-4-methylsulfonylaminophenyl ketone was suspended in 14 ml of ethyl orthoformate. Thereto was dropwise added 2.0 g of 70% (w/w) perchloric acid in 10 minutes with ice-cooling. The mixture was stirred for 1.5 hours at 20°-25° C. The reaction mixture was mixed with 20 ml of diisopropyl ether. The resulting crystal was collected by filtration and mixed with 20 ml of water. The mixture was refluxed for 5 minutes and then cooled. 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 dissolved in 14 ml of a 1N aqueous sodium hydroxide solution. The mixture was stirred for 30 minutes at 20°-25° C. The reaction mixture was adjusted to pH 2 with 6N hydrochloric acid. The resulting crystal was collected by filtration and recrystallized from a mixed solvent of N,N-dimethylformamide and water to obtain 1.0 g (yield: 59%) of 6-hydroxy-7-methylsulfonylamino-4H-1-benzopyran-4-one having a melting point of >250° C.

Provenance & Evidence