N-bromobutanimide → tert-Butyl 2-(4-bromo-5-oxo-2,5-dihydrofuran-3-yl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate
Reaction equation
[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.[Br:25]N1C(=O)CCC1=O>C(Cl)Cl>[Br:25][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]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
tert-butyl 1-oxo-2-(5-oxo-2,5-dihydrofuran-3-yl)-2,8-diazaspiro[4.5]decane-8-carboxylate (I-16, Step A) (2.73 g, 8.12 mmol) was dissolved in DCM (70 mL) and was treated with N-bromosuccinimide (1.73 g, 9.74 mmol) at 25° C. and the resulting mixture was stirred overnight at room temperature. The next day, the reaction mixture was diluted with DCM and was washed with water and brine then dried over Na2SO4. Removing solvent gave crude product that was purified by silica gel column chromatography (80 g RediSep Gold Column) using (25-80) % EtOAc/Hexanes as mobile phase to afford the title compound.