N[C:2]1[CH:3]=[C:4]([C@@:8]2([CH3:24])[N:13]([CH2:14][C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=3)[C:12](=[O:23])[CH2:11][O:10][CH2:9]2)[CH:5]=[CH:6][CH:7]=1.C([O-])(C)(C)C.[K+].COC1C=CC(C[Br:38])=CC=1>CN(C)C=O>[Br:38][C:2]1[CH:3]=[C:4]([C@@:8]2([CH3:24])[N:13]([CH2:14][C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=3)[C:12](=[O:23])[CH2:11][O:10][CH2:9]2)[CH:5]=[CH:6][CH:7]=1A solution of (R)-5-(3-amino-phenyl)-4-(4-methoxy-benzyl)-5-methyl-morpholin-3-one (1.0 g, 3.7 mmol) in N,N-dimethylformamide was added within 5 minutes at 0° C. to a solution of potassium tert-butanolate (0.636 g, 5.7 mmol). After stirring at 0° C. for 30 minutes the light yellow solution was cooled to −4° C. and treated with a solution of 4-methoxybenzylbromide (1.12 g, 5.6 mmol) in N,N-dimethylformamide (4 ml). The reaction mixture was left to warm to room temperature, then the solvent was evaporated at reduced pressure, and the residue treated with saturated ammonium chloride solution (50 ml) and ethyl acetate (100 ml). The organic layer was separated, washed with brine (50 ml), dried over sodium sulfate, and evaporated at reduced pressure. The crude product was purified by chromatography on silica gel using a gradient of heptane and ethyl acetate=100/0 to 50/50 as the eluent. The (R)-5-(3-bromo-phenyl)-4-(4-methoxy-benzyl)-5-methyl-morpholin-3-one was obtained as colorless oil (1.19 g, 83% of theory). Mass (calculated) C19H20BrNO3 [390.275]; (found) [M+H]+=390, [M+2-H]+=392.
読み込み中…
