反应详情

3 g of N-(3,4-dichlorophenyl)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide were dissolved in 50 ml of THF distilled beforehand over sodium/benzophenone. 1 g of sodium hydride (NaH), at 60% in oil, was added. The reaction mixture was stirred for 30 min and then cooled to 0-5°. 2.3 g of ethyl chloroformate, in solution in 10 ml of THF, were added without exceeding 5° C. After maintaining overnight at room temperature, the reaction mixture was poured onto 100 ml of ice-cold water and then extracted with 4×50 ml of dichloromethane. The organic phase was washed with 20% sodium chloride, dried over sodium sulfate and evaporated to dryness. The residue was purified by silica chromatography (eluent: 1/1 heptane/dichloromethane). 1.25 g of 3-(3,4-dichlorophenyl)-5-methyl-5-(trifluoromethyl)oxazolidine-2,4-dione was obtained, for a yield 38%.

1. temperaturecooled to 0-5°
2. customwithout exceeding 5° C
3. extractionextracted with 4×50 ml of dichloromethane
4. washThe organic phase was washed with 20% sodium chloride
5. dry with materialdried over sodium sulfate
6. customevaporated to dryness
7. customThe residue was purified by silica chromatography (eluent: 1/1 heptane/dichloromethane)