Tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,2,3,6-tetrahydropyridine-1-carboxylate → 1,2,3,6-Tetrahydropyridine-4-boronic acid, pinacol ester hydrochloride
Reaction equation
[CH3:1][C:2]1([CH3:22])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH2:14][CH2:13][N:12](C(OC(C)(C)C)=O)[CH2:11][CH:10]=2)[O:3]1.[ClH:23].CO>>[ClH:23].[CH3:7][C:6]1([CH3:8])[C:2]([CH3:1])([CH3:22])[O:3][B:4]([C:9]2[CH2:14][CH2:13][NH:12][CH2:11][CH:10]=2)[O:5]1Participants
3
Procedure
The mixture of tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (4.0 g, 12.9 mmol) in HCl/MeOH (20 mL) was stirred at room temperature for 1 hour. Then it was concentrated to give 4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)-1,2,3,6-tetrahydro-pyridine hydrochloride (2.9 g, 11.8 mmol, yield: 91.4%) which was used in the next step without further purification. ESI-MS (M+1): 210 calc. for C11H20BNO2 209.