反应详情

A solution of (R)-methyl 2-(tert-butoxycarbonylamino)-2-(2-((S)-3-(hydroxymethyl)-3,4-dihydroisoquinolin-2(1H)-yl)ethyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (0.187 g, 0.334 mmol) in 6 N HCl (5 mL) was heated to a gentle reflux for 16 h. After cooling to room temperature, the reaction mixture was transferred to a separatory funnel, diluted with deionized water (5 mL) and washed with dichloromethane (3×5 mL). The aqueous layer was frozen in liquid nitrogen and lyophilized to give (R)-2-amino-6-borono-2-(2-((S)-3-(hydroxymethyl)-3,4-dihydroisoquinolin-2(1H)-yl)ethyl)hexanoic acid dihydrochloride as an off-white foam (0.122 g, 89%). 1H NMR (D2O, 300 MHz) δ 7.26-7.08 (m, 4H), 3.89-375 (m, 1H), 3.78-3.65 (m, 1H), 3.61-3.50 (m, 1H), 3.41-3.18 (m, 1H), 3.10-3.00 (m, 1H), 2.99-2.75 (m, 2H), 2.35-2.20 (m, 2H), 1.84-1.60 (m, 2H), 1.31-1.16 (m, 2H), 1.15-1.00 (m, 2H), 0.66-0.50 (m, 2H); ESI-LCMS m/z calcd for C18H29BN2O5: expected 364.2. found 365.2 (M+H)+.

1. temperaturea gentle reflux for 16 h
2. customthe reaction mixture was transferred to a separatory funnel
3. washwashed with dichloromethane (3×5 mL)
4. temperatureThe aqueous layer was frozen in liquid nitrogen