Hydrochloric Acid → 3-(5-(3,5-Dichlorophenyl)-4,5-dihydro-5-trifluoromethyl-3-isoxazolyl)aniline

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Reaction Conditions

Reaction Steps

To a solution of 5-(3,5-dichloro-phenyl)-3-(3-nitro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole (15.0 g, 37 mmol) (Example I2) in isopropanol (120 ml) was added tin(II) chloride (25 g, 133 mmol). The mixture was cooled to 0° C. and aqueous hydrochloric acid (concentrated) (23 ml) was added slowly at 0° C. The reaction mixture was heated to 80° C. for 2 hours. Then ⅓ of the total volume of isopropanol was evaporated. Water (100 ml) was added to the mixture and aqueous sodium hydroxide (4N) was added to adjust the pH to 8-9. The aqueous phase was extracted three times with ethyl acetate (200 ml). The combined organic extracts were dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: cyclohexane/ethyl acetate 1:1) to give 3-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-phenylamine (8.1 g, 58% yield). 1H-NMR (CDCl3, 400 MHz): 7.56 (m, 2H), 7.43 (m, 1H), 7.20 (t, 1H), 7.05 (m, 1H), 6.97 (m, 1H), 6.78 (m, 1H), 4.08 (d, 1H), 3.8 (s, 1H), 3.68 (d, 1H).

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