Triethylamine → 3-(4-Bromo-3-methylphenyl)-5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazole

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Reaction Steps

4-Bromo-3-methyl-benzaldehyde oxime (1.3 g) (Example I2) and N-chlorosuccinimide (“NCS”) (1.8 g) were dissolved in N,N-dimethylformamide (15 ml). The reaction mixture was stirred at ambient temperature for 90 minutes. A solution of 1,3-dichloro-5-(1-trifluoromethyl-vinyl)-benzene (1.3 g) (prepared according to WO 2005/085216) and triethylamine (1.9 ml) in N,N-dimethylformamide (15 ml) was added and the reaction mixture was stirred at ambient temperature for 18 hours. The reaction mixture was diluted with water and ethyl acetate and the phases were separated. The organic phase was washed twice with water and the aqueous phases were extracted twice with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel (eluent: cyclohexane/dichloromethane 4:1) to give 3-(4-bromo-3-methyl-phenyl)-5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole (1.57 g). 1H-NMR (400 MHz, CDCl3): 7.40 (m, 6H), 4.05 (d, 1H), 3.65 (d, 1H), 2.40 (s, 3H) ppm.

Provenance & Evidence