[NH:1]1[CH2:6][CH2:5][CH:4]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[CH2:3][CH2:2]1.C(O[BH-](O[C:25](=O)[CH3:26])OC(=O)C)(=O)C.[Na+].[C:29](O)(=O)[CH3:30].C(=O)(O)[O-].[Na+].O1C[CH2:41][CH2:40][CH2:39]1>O>[C:25]1([CH2:26][N:1]2[CH2:2][CH2:3][CH:4]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:11])([CH3:13])[CH3:12])[CH2:5][CH2:6]2)[CH2:30][CH2:29][CH2:41][CH2:40][CH:39]=1A mixture of tert-butyl N-(piperidin-4-yl)carbamate (5.3 g, 26.5 mmol), 1-cyclohexane-1-carboxaldehyde (3.5 g, 31.8 mmol), sodium triacetoxyborohydride (7.29 g, 34.4 mmol), acetic acid (0.5 ml) and tetrahydrofuran (dehydrated) (80 ml) was stirred at room temperature for 85 hours and 30 minutes. Water and sodium bicarbonate were added to the reaction mixture, which was stirred and then extracted with ethyl acetate twice. The organic layer was washed with brine and dried over anhydrous sodium sulfate, and the solvent was distilled off. The residue was purified by silica gel column chromatography (NH silica gel, elution solvent: ethyl acetate/heptane) to give the title compound (7.47 g, yield: 95.7%).
Loading…
