[O:1]=[C:2]1[C:6]2([CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][CH2:7]2)[N:5]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH2:4][NH:3]1.Br[C@@H:26]([C:31]1[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=1)[C:27]([O:29][CH3:30])=[O:28].C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O>[CH3:30][O:29][C:27](=[O:28])[C@@H:26]([N:3]1[C:2](=[O:1])[C:6]2([CH2:7][CH2:8][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:10][CH2:11]2)[N:5]([C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)[CH2:4]1)[C:31]1[CH:32]=[CH:33][CH:34]=[CH:35][CH:36]=1A mixture of tert-butyl 4-oxo-1-phenyl-1,3,8-triazaspiro[4.5]decane-8-carboxylate (300 mg, 0.905 mmol, 1 equiv), (S)-methyl 2-bromo-2-phenylacetate (207.4 mg, 0.905 mmol, 1 equiv) and potassium carbonate (312.7 mg, 2.26 mmol, 2.5 equiv) in N,N-dimethylformamide was stirred at 65° C. for 2 hours. The reaction mixture was cooled to ambient temperature and the mixture was partitioned between ethyl acetate and water. The organic layer was further washed with brine, dried over MgSO4, and concentrated in vacuo. The resulting residue was purified using the Biotage flash chromatography system (SNAP 50 g cartridge, Rf=0.4, 20% ethyl acetate/hexanes) to afford (S)-tert-butyl 3-(2-methoxy-2-oxo-1-phenylethyl)-4-oxo-1-phenyl-1,3,8-triazaspiro[4.5]decane-8-carboxylate as an oil (183 mg, 42.3%). MS for C27H33N3O5 m/z 479.57 (M+H)+.
Wird geladen…