反应详情

温度

75 °C

A solution of ethyl 5-[4-(trifluoromethyl)phenyl]-4,5-dihydroisoxazole-3-carboxylate (3.3 g) was stirred in toluene (15 ml), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (100 g) was then added in portions, followed by a portion of 3A molecular sieves, and the resulting mixture was stirred at 75° C. for 2 days. After cooling, ether was added and the mixture filtered through a layer anhydrous sodium sulfate. Solvent was evaporated under reduced pressure, and the residue was purified by column chromatography, to provide ethyl 5-[4-(trifluoromethyl)phenyl]isoxazole-3-carboxylate, a compound of formula (23).

1. temperatureAfter cooling
2. filtrationthe mixture filtered through a layer anhydrous sodium sulfate
3. customSolvent was evaporated under reduced pressure
4. customthe residue was purified by column chromatography