C(O[C:6]([N:8]1[CH2:13][CH2:12][CH:11]([O:14][C:15]2[CH:20]=[CH:19][C:18]([N+:21]([O-:23])=[O:22])=[CH:17][C:16]=2[Cl:24])[CH2:10][CH:9]1[CH3:25])=O)(C)(C)C.C=O.C(=O)([O-])[O-].[K+].[K+]>C(O)=O>[Cl:24][C:16]1[CH:17]=[C:18]([N+:21]([O-:23])=[O:22])[CH:19]=[CH:20][C:15]=1[O:14][CH:11]1[CH2:12][CH2:13][N:8]([CH3:6])[CH:9]([CH3:25])[CH2:10]1To a suspension of 4-(1-t-butoxycarbonyl-2-methylpiperidin-4-yloxy)-3-chloronitrobenzene (1.15 g) obtained in reference example 85 in 90% formic acid (3.10 g) was added 37% formaldehyde (2.50 g), and the resulting mixture was stirred at 100° C. for 2 hours. After cooling to room temperature, the reaction mixture was neutralized with an aqueous potassium carbonate solution and extracted with ethyl acetate. The extract was washed with a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and evaporated in vacuo. The residue obtained was purified by chromatography on a silica gel column using a mixed solvent of dichloromethane and methanol (9:1) as the eluent to afford the title compound (0.80 g, yield: 90%) as a yellow oil.
読み込み中…
