反应详情

1.5 g of 2-fluoro-4-methyl-5-(2,2,2-trifluoroethylthio)phenylhydrazine was dissolved in 70 mL of tetrahydrofuran, and 0.83 g of malonyl chloride was added under cooling with ice. Stirring was carried out under reflux with heating for 5 hours, and the solvent was distilled off under reduced pressure. To the obtained residue, 20 mL of dichloromethane and 2 mL of methanol were added, and 0.7 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=1:1) to obtain 0.14 g of 1-{2-fluoro-4-methyl-5-(2,2,2-trifluoroethylthio)phenyl}-5-hydroxy-3-methoxypyrazole.

1. temperatureunder cooling with ice
2. temperatureunder reflux
3. temperaturewith heating for 5 hours
4. distillationthe solvent was distilled off under reduced pressure
5. additionTo the obtained residue, 20 mL of dichloromethane and 2 mL of methanol were added
6. addition0.7 mL of a diethyl ether solution (2.0 mol/L) of trimethylsilyldiazomethane was added
7. temperatureunder cooling with ice
8. stirringby stirring at room temperature for 5 hours
9. distillationThen, the solvent was distilled off under reduced pressure
10. customthe obtained residue was purified by column chromatography (developing solvent ethyl acetate:hexane=1:1)