1,2,3-Trichloro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene → 3,3-dimethyl-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)benzo[c][1,2]oxaborol-1(3H)-ol

Participants

Reaction Steps

To a solution of N,1-dihydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbimidoyl chloride (850 mg, 3.55 mmol) and 1,2,3-trichloro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene (1.47 g, 5.32 mmol) in DMF (10 mL) at rt was added TEA (0.5 mL, 3.55 mmol). The reaction mixture was stirred at rt for 18 h, poured into ice-water and extracted with EA (20 mL). The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography to give the desired title compound 3,3-dimethyl-5-(5-(3,4,5-trichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)benzo[c][1,2]oxaborol-1(3H)-ol (510 mg; 30% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 9.25 (s, 1H), 7.86 (s, 2H), 7.78 (s, 2H), 7.72 (d, J=7.2 Hz, 1H), 4.46 (d, J=19.2 Hz, 1H), 4.35 (d, J=18.4 Hz, 1H), 1.49 (s, 6H) ppm; HPLC purity: 95.3% at 220 nm and 96.8% at 254 nm; MS: m/z=478.4 (M+, ESI+).

Provenance & Evidence