Diisopropylethylamine → 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-N-((1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)methyl)-N,2-di-ethylbenzamide

Participants

Reaction Steps

To a cold solution of 3,3-dimethyl-6-((methylamino)methyl)benzo[c][1,2]-oxaborol-1(3H)-ol (246 mg, 1.2 mmol), 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-2-methylbenzoic acid (502 mg, 1.2 mmol) and 2-bromo-1-ethylpyridinium tetrafluoroborate (BEP) (292 mg, 1.32 mmol) in DCM (10 mL) was added DIPEA (464 mg, 3.6 mmol). The reaction mixture was stirred at rt overnight. Water (20 mL) was added and the mixture was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by prep-HPLC to give 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-N-((1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)methyl)-N,2-di-ethylbenzamide (84 mg; yield 11.6%) as a white solid. HPLC purity: 98.30% at 220 nm and 98.87% at 254 nm; MS: m/z=604.9 (M+1, ESI+).

Provenance & Evidence