N-bromobutanimide → tert-Butyl 2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate
反応式
[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)[CH2:5][CH2:4][N:3]1[C:19]1[CH2:20][O:21][C:22](=[O:24])[CH:23]=1.C1C(=O)N([Br:32])C(=O)C1>C(Cl)Cl>[Br:32][C:23]1[C:22](=[O:24])[O:21][CH2:20][C:19]=1[N:3]1[CH2:4][CH2:5][C:6]2([CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:17])([CH3:18])[CH3:16])=[O:13])[CH2:8][CH2:7]2)[C:2]1=[O:1]参加物
4
実験手順
tert-Butyl 1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate (I-16, Step A) (784 mg, 2.33 mmol) was dissolved in DCM (20 mL) and was treated with NBS (498 mg, 2.80 mmol) at 25° C. for 12 hours. The reaction mixture was diluted with DCM (20 mL), washed with water (20 mL) and brine (20 mL), dried over anhydrous sodium sulfate and filtered. The filtrates were concentrated and the crude product was purified by column chromatography (ISCO 40 g silica gel column), eluting with 50-100% ethyl acetatehexane gradient to give the title compound.