Triethylamine → Methyl 4-[5-(3,5-dichlorophenyl)-4,5-dihydro-5-(trifluoromethyl)-3-isoxazolyl]-1-naphthalenecarboxylate

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Reaction Steps

N-Chlorosuccinimide (1.16 g, 8.72 mmol) was added to a stirred solution of methyl 4-[(hydroxyimino)methyl]-1-naphthalenecarboxylate (i.e. the product of Step A, 1.0 g, 4.36 mmol) in N,N-dimethylformamide (5.0 mL). This mixture was stirred for 1.5 h at room temperature, and then a solution of 1,3-dichloro-5-[1-(trifluoromethyl)ethenyl]benzene (3.20 g, 13.1 mmol, prepared from commercially available 2-bromo-3,3,3-trifluoropropene by the method described in J. Fluorine Chem. 1999, 95, 167-170) and triethylamine (6.1 mL, 43.6 mmol) in N,N-dimethylformamide (4.0 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 combined organic extracts were 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 pale yellow oil (700 mg). 1H NMR (CDCl3): δ 8.88 (d, 1H), 8.80 (d, 1H), 8.10 (d, 1H), 7.68 (m, 2H), 7.55 (m, 3H), 7.46 (dd, 1H), 4.27 (d, 1H), 4.03 (s, 3H), 3.91 (d, 1H).

Provenance & Evidence