Water → 5-(4-aminobutylamino)-6,8-difluoro-2-(3-fluoro-4-pivaloylaminophenyl)-4H-1-benzopyran-4-one

Participants

Reaction Steps

332 mg (0.682 mmol) of the above 5-(4-azidobutylamino)-6, 8-difluoro-2-(3-fluoro-4-pivaloylaminophenyl)-4H-1-benzopyran-4-one was dissolved in 20 mL of tetrahydrofuran, 272 mg (1.02 mmol) of triphenylphosphine and 20 mL of water were added and the mixture was stirred at room temperature for 22 hours. Ethyl acetate was added to the reaction solution, and the organic layer was separated, washed with an aqueous saturated solution of sodium chloride and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure and the residue was purified by silica gel column chromatography (chloroform:methanol=20:1-chloroform:methanol:aqueous ammonia=9:1:1) to give 260 mg of 5-(4-aminobutylamino)-6,8-difluoro-2-(3-fluoro-4-pivaloylaminophenyl)-4H-1-benzopyran-4-one (yield: 83%).

Provenance & Evidence