反应详情

To a solution of methyl 1-{[2-ethyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]methyl}-3-azetidinecarboxylate (5.23 g, 14.56 mmol) in Methanol (50 mL) was added potassium hydrogen fluoride (16.17 mL, 72.8 mmol). The mixture was stirred at rt for an hour. LCMS showed that the starting material was consumed completely. The solvent was removed under the reduced pressure and the residue was acidified with HCl (1.0 M) to pH value around 3 then extracted with EtOAc (50 mL). The aqueous phase was adjusted to pH value around 6 with sat. NaHCO3 solution, the target product was collected by filtering and dried in vacuum to give (2-ethyl-3-((3-(methoxycarbonyl)azetidin-1-yl)methyl)phenyl)boronic acid (2.5 g) as a brown solid. δH (DMSO-d6, 600 MHz): 1.02 (2H, m), 2.81 (2H, m), 3.70 (4H, m), 4.23 (4H, m), 4.33 (2H, m), 7.00 (2H, m), 7.43 (1H, m), 9.93 (1H, m).

1. customwas consumed completely
2. customThe solvent was removed under the reduced pressure
3. extractionthen extracted with EtOAc (50 mL)
4. customthe target product was collected
5. filtrationby filtering
6. customdried in vacuum