反应详情

Then, 1.50 g of 1-acetyl-2-{2-fluoro-4-methyl-5-(2,2,2-trifluoroethylthio)phenyl}pyrazolidine-3,5-dione was dissolved in 50 mL of dichloromethane, 5 mL of methanol was added, and 2.1 mL of a diethyl ether solution (2.0 mol/L) of trimethylsilyldiazomethane was added under cooling with ice, followed by stirring at room temperature for 5 hours. Then, the solvent was distilled off under reduced pressure, and the obtained residue was purified by column chromatography (developing solvent ethyl acetate:hexane=1:2) to obtain 0.69 g of 2-acetyl-1-{2-fluoro-4-methyl-5-(2,2,2-trifluoroethylthio)phenyl}-5-methoxypyrazol-3-one.

1. temperatureunder cooling with ice
2. distillationThen, the solvent was distilled off under reduced pressure
3. customthe obtained residue was purified by column chromatography (developing solvent ethyl acetate:hexane=1:2)