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

Participants

Reaction Steps

To a solution of 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-2-methylbenzoic acid (320 mg, 0.76 mmol) and HATU (456 mg, 1.2 mmol) in DMF (18 mL), DIPEA (310 mg, 2.4 mmol) was added. The reaction mixture was stirred at rt for 10 min and crude 6-(2-aminoethyl)-3,3-dimethylbenzo[c][1,2]oxaborol-1(3H)-ol hydrochloride (1 mmol) was added. The reaction mixture was continued to stir overnight. Water 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 the final title compound 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazol-3-yl)-N-(2-(1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)ethyl)-2-methylbenzamide (276 mg; yield 54.4%) as a white solid. 1H NMR (500 MHz, DMSO-d6) δ 8.99 (s, 1H), 8.42 (t, J=6.0 Hz, 1H), 7.82 (t, J=2.0 Hz, 1H), 7.53-7.63 (m, 5H), 7.33-7.35 (m, 3H), 4.35 (d, J=18.5 Hz, 1 H), 4.30 (d, J=18.5 Hz, 1 H), 3.50 (q, J=7.5 Hz, 2H), 2.88 (t, J=7.5 Hz, 2H), 2.23 (s, 3 H), 1.43 (s, 6H) ppm;

Provenance & Evidence