反应详情

(R)-tert-butyl 1-(1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborol-6-ylamino)-1-oxo-3-(4-(trifluoromethyl)phenyl)propan-2-ylcarbamate (CLXII) (1.00 g, 2.1 mmol) was treated with HCl/EtOAc (4.2 M, 15 mL) and was stirred for 30 minutes at room temperature. The solvent was removed under vacuum, and the residue was triturated with hexane to give the hydrochloride salt of (R)-2-amino-N-(1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)-3-(4-(trifluoromethyl)phenyl)propanamide (CLXIII) as a white solid (0.86 g, 2.01 mmol, 94% yield). 1H NMR (DMSO-d6) δ ppm 1.39 (s, 6H), 3.19 (dd, J=13 Hz, J=13 Hz, 1H), 3.29-3.32 (m, 1H), 4.33-4.40 (m, 1H), 7.34 (d, J=8 Hz, 1H), 7.55 (d, J=7 Hz, 2H), 7.60 (d, J=8 Hz, 1H), 7.66 (d, J=7 Hz, 2H), 7.86 (s, 1H), 8.45 (brs, 3H), 9.1 (s, 1H), 11.03 (s, 1H); 19F NMR (DMSO-d6) δ ppm −60.25 (s, 3F). ESIMS found for C19H20BF3N2O3 m/z 393.4 (M+H).

1. customThe solvent was removed under vacuum
2. customthe residue was triturated with hexane