反应详情

温度

0 °C

To a solution of N-butyl-4-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-2-methyl-benzamide (made as described in EP 1,731,512) (1670 mg, 4.13 mmol) and N,N-diisopropylamine (880 mg, 8.69 mmol) in dry tetrahydrofuran (10 ml) was added n-butyl lithium (“n-BuLi”) (1.55M in hexane) (5.6 ml, 8.69 mmol) at −90° C. The reaction mixture was allowed to warm to 0° C. over a period of 2 hours and quenched by addition of aqueous ammonium chloride (saturated). The mixture was extracted several times with diethyl ether. The combined organic extracts were dried over magnesium sulfate and concentrated. The residue was purified by chromatography on silica gel (eluent: hexane/ethyl acetate 2:1) to give N-butyl-4-[3-(3,5-dichloro-phenyl)-4,4,4-trifluoro-1-hydroxyimino-but-2-enyl]-2-methyl-benzamide (1180 mg, 70% yield) as a yellow resin. 1H-NMR (CDCl3, 300 MHz): 8.52 (bs, 1H), 7.45-7.36 (m, 6H), 6.75 (s, 1H), 5.81 (m, 1H), 3.46-3.43 (m, 2H), 2.47 (s, 3H), 1.54-1.39 (m, 4H), 0.97 (t, 3H) ppm.

1. customquenched by addition of aqueous ammonium chloride (saturated)
2. extractionThe mixture was extracted several times with diethyl ether
3. dry with materialThe combined organic extracts were dried over magnesium sulfate
4. concentrationconcentrated
5. customThe residue was purified by chromatography on silica gel (eluent: hexane/ethyl acetate 2:1)