Acetic Acid → HCID 10523682, compound

Participants

Reaction Conditions

Reaction Steps

6.02 g (11.9 mmol) of 6,8-difluoro-2-(3-fluoro-4-pivaloylaminophenyl)-7-hydroxymethyl-5-pivaloylamino-4H-1-benzopyran-4-one obtained in Example 118 (4) was dissolved in a mixed solvent of 160 mL of acetic acid and 40 mL of concentrated sulfuric acid and the solution was stirred at 100° C. for 35 minutes. The reaction solution was cooled on ice, poured into ice water and the mixture was extracted twice with ethyl acetate. The organic layer was washed twice with a 1N aqueous solution of sodium hydroxide, once with water and once with an aqueous saturated solution of sodium chloride and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, the residue was purified by silica gel column chromatography (chloroform:methanol=100:1) and recrystallized from chloroform/methanol/n=hexane to give 2.43 g of Compound 123 (yield: 54%).

Provenance & Evidence