反应详情

12 g of 2-fluoro-4-methyl-5-(2,2,2-trifluoroethylthio)phenylhydrazine was dissolved in 200 mL of tetrahydrofuran, and 100 mL of water was added. To this solution, 16 g of potassium carbonate and 8.1 g of 3-bromopropionyl chloride were added, followed by stirring at room temperature for 5 hours. The aqueous layer was neutralized to the vicinity of pH 2 with 6N hydrochloric acid. Then, the solvent was distilled off under reduced pressure, and the residue was subjected to extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain a solid, which was washed with hexane. Then, this solid was dissolved in 200 mL of toluene, and 100mL of water was added. Then, 3.7 g of potassium permanganate and tetra n-butyl ammonium bromide in a catalytic amount were added, followed by stirring at room temperature for 10 minutes. Then, an insoluble solid was removed by filtration, and the organic layer was dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure, and the solid was washed with hexane to obtain 8.7 g of pale yellow crystals (melting point: 166-168° C.).

1. distillationThen, the solvent was distilled off under reduced pressure
2. extractionthe residue was subjected to extraction with ethyl acetate
3. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
4. distillationthe solvent was distilled off under reduced pressure
5. customto obtain a solid, which
6. washwas washed with hexane
7. dissolutionThen, this solid was dissolved in 200 mL of toluene
8. addition100mL of water was added
9. additionThen, 3.7 g of potassium permanganate and tetra n-butyl ammonium bromide in a catalytic amount were added
10. stirringby stirring at room temperature for 10 minutes
11. customThen, an insoluble solid was removed by filtration
12. dry with materialthe organic layer was dried over anhydrous magnesium sulfate
13. distillationThen, the solvent was distilled off under reduced pressure
14. washthe solid was washed with hexane