Triethylamine → 3-(5-(3,5-Dichlorophenyl)-4,5-dihydro-5-trifluoromethyl-3-isoxazolyl)nitrobenzene

Participants

Reaction Steps

3-Nitro-benzaldehyde oxime (commercially available) (6.15 g, 37.0 mmol) and N-chlorosuccinimide (“NCS”) (4.94 g, 37.0 mmol) were dissolved in N,N-dimethylformamide (65 ml). This mixture was stirred at ambient temperature for 90 minutes. A solution of 1,3-dichloro-5-(1-trifluoromethyl-vinyl)-benzene (which was made as described, for example, in WO 05/085216) (8.53 mg, 37.0 mmol) and triethylamine (5.15 ml, 37.0 mmol) in N,N-dimethylformamide (70 ml) was added and the reaction mixture was stirred at ambient temperature for 18 hours. Water (300 ml) and ethyl acetate (300 ml) were added. The phases were separated and the organic phase was washed twice with water. The aqueous phases were extracted with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: cyclohexane/ethyl acetate 2:1) to give 5-(3,5-dichloro-phenyl)-3-(3-nitro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole (14.5 g, 97% yield). The residue was used without further purification or analysis.

Provenance & Evidence