[O:1]=[C:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:4][CH2:3]1.CO[CH:17](OC)[N:18]([CH3:20])[CH3:19]>CN(C)C=O>[O:1]=[C:2]1[CH2:3][CH2:4][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:6][C:7]1=[CH:17][N:18]([CH3:20])[CH3:19]A solution of tert-butyl 4-oxo-1-piperidinecarboxylate (8.73 g, 44 mmol) and N,N-dimethylformamide dimethyl acetal (5.8 mL, 44 mmol) in 80 mL of dry N,N-dimethylformamide was warmed at 80° C. for 18 h. The solution was cooled and concentrated under reduced pressure, and the residue was partitioned between ethyl acetate and water. The mixture was filtered through a pad of Celite, and the organic layer was separated, washed with saturated brine, dried over magnesium sulfate and concentrated under reduced pressure to afford the title compound as an orange oil.
読み込み中…