Triethylamine → 5-[3,5-Bis(trifluoromethyl)phenyl]-3-(4-bromo-1-naphthalenyl)-4,5-dihydro-5-(trifluoromethyl)isoxazole

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Reaction Steps

N-Chlorosuccinimide (2.05 g, 15.5 mmol) was added to a solution of 4-bromo-1-naphthalenecarboxaldehyde oxime (i.e. the product of Example 4, Step A, 3.20 g, 12.8 mmol) in N,N-dimethylformamide (20.0 mL). The reaction mixture was stirred for 1 h at room temperature, and then a solution of 1,3-bis(trifluoromethyl)-5-[1-(trifluoromethyl)ethenyl]benzene (5.13 g, 16.6 mmol, prepared according to the method described in J. Org. Chem. 1959, 24, 238-239) and triethylamine (5.4 mL, 38.4 mmol) in N,N-dimethylformamide (10.0 mL) was added. After stirring for an additional 2 h at room temperature, the reaction mixture was diluted with water and extracted with ethyl acetate. The organic extract was washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by chromatography on silica gel eluted with ethyl acetate/hexanes to afford the title compound as a white solid (3.2 g). 1H NMR (CDCl3): δ 8.89 (m, 1H), 8.35 (m, 1H), 8.13 (s, 2H), 7.99 (s, 1H), 7.81 (d, 1H), 7.69 (m, 2H), 7.37 (d, 1H), 4.38 (d, 1H), 3.94 (d, 3H).

Provenance & Evidence