反应详情

To a solution of the crude compound 4-fluoro-N,1-dihydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbimidoyl chloride (180 mg. 0.70 mmol) and 1,3-dichloro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene (203 mg, 0.84 mmol) in DMF (5 mL) at rt was added TEA (117 μL, 0.84 mmol). The reaction mixture was stirred for 12 h, poured into ice-water and extracted three times with ethyl acetate. The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by prep-TLC eluted with PE-EA (3:2) and then purified by combiflash to give the title compound 5-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-4-fluoro-3,3-dimethylbenzo[c][1,2]oxaborol-1(3H)-ol[80 mg; yield 24.8% over the last 3 steps] as a white solid. 1H NMR (500 MHz, DMSO-d6): δ 9.479 (s, 1H), 7.810 (t, J=1.5 Hz, 1H), 7.753 (t, J=7.5 Hz, 1H), 7.671 (d, J=1.5 Hz, 2H), 7.582 (d, J=7.5 Hz, 1H), 4.376 (d, J=18.0 Hz, 1H), 4.270 (d, J=18.0 Hz, 1H), 1.55 (s, 6H) ppm; HPLC purity: 100% at 220 nm and 100% at 254 nm; MS: m/z=462.0 (M+1, ESI+).

1. extractionextracted three times with ethyl acetate
2. washThe organic layer was washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified
7. washby prep-TLC eluted with PE-EA (3:2)
8. custompurified by combiflash