反应详情

To a solution of 4-(chloro(hydroxyimino)methyl)-2-methylbenzoic acid (5.1 g, 23.8 mmol) in DMF (30 mL) at 0° C. was added 1,3-dichloro-2-fluoro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene (7.4 g, 28.6 mmol) followed by Et3N (4.8 g, 47.6 mmol). The reaction mixture was stirred at rt for 18 h, poured into ice-water (30 mL) and extracted with ethyl acetate (60 mL×3). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel eluted with PE:EA (1:1) to EA: MeOH (10:1) to give 4-(5-(3,5-dichloro-4-fluorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-2-methylbenzoic acid (6 g; yield 58% over 3 steps) as a white solid. MS: m/z=435.8 (M+1, ESI+).

1. extractionextracted with ethyl acetate (60 mL×3)
2. washThe combined organic layers were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by column chromatography over silica gel
7. washeluted with PE