Ethyl Acetate → 5-(5-(3,4-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-3,3-dimethyl-benzo[c][1,2]oxaborol-1(3H)-ol

Participants

Reaction Steps

To a solution of (Z)—N,1-dihydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbimidoyl chloride (397 mg, 1.66 mmol) and 1,2-dichloro-4-(3,3,3-trifluoroprop-1-en-2-yl)benzene (400 mg, 1.66 mmol) in DMF (5 mL) at rt was added TEA (168 mg, 1.66 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 over silica gel eluted with PE:EA (6:1) to give the final title compound 5-(5-(3,4-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-3,3-dimethyl-benzo[c][1,2]oxaborol-1(3H)-ol (180 mg; yield 24.4%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 9.20 (s, 1H), 7.83-7.60 (m, 5H), 4.45 (d, J=18.8 Hz, 1H), 4.26 (d, J=18.4 Hz, 1H), 1.48 (s,6H) ppm; HPLC purity: 96.8% at 220 nm and 97.5% at 254 nm; MS: m/z=444.3 (M+, ESI+).

Provenance & Evidence