反应详情

A solution of 2-acetamido-2-(1-benzylpiperidin-4-yl)-N-tert-butyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide (510 mg, 0.97 mmol) in 6 N HCl (15 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 (15 mL) and washed with dichloromethane (3×25 mL). The aqueous layer was concentrated to give an off-white solid that was purified by HPLC (5-95% acetonitrile in water). The fractions containing product were concentrated, redissolved in deionized water (15 mL), frozen in liquid nitrogen and lyophilized to give 2-amino-2-(1-benzylpiperidin-4-yl)-6-boronohexanoic acid (210 mg, 62%) as its dihydrochloride salt and trihydrate. 1H NMR (D2O, 500 MHz) δ 7.37-7.43 (m, 5H), 4.21 (s, 2H), 3.51 (brt, J=10 Hz, 2H), 2.92-2.99 (m, 2H), 2.02-2.10 (m, 2H), 1.66-1.84 (m, 4H), 1.41 (dq, J1=13.0 Hz, J1=4.0 Hz, 1H), 1.29-1.35 (m, 2H), 1.23-1.28 (m, 1H), 1.08-1.12 (m, 1H), 0.68 (t; J=8.0 Hz, 2H). ESI MS found for C18H29BFN2O4 m/z [331.6 (M+1−18) 13%, 313.6 (M+1−2×18) 100%, 329.6 (M−1−18) 100%]. Anal. Calcd for C18H29BN2O4×2HCl×3H2O: C, 45.49; H, 7.85; N, 5.89. Found C, 45.60; H, 7.10; N, 5.55.

1. temperaturea gentle reflux for 16 h
2. customthe reaction mixture was transferred to a separatory funnel
3. washwashed with dichloromethane (3×25 mL)
4. concentrationThe aqueous layer was concentrated
5. customto give an off-white solid
6. customthat was purified by HPLC (5-95% acetonitrile in water)
7. additionThe fractions containing product
8. concentrationwere concentrated
9. dissolutionredissolved in deionized water (15 mL)
10. temperaturefrozen in liquid nitrogen