N-bromobutanimide → tert-butyl [(3S)-7-bromo-2-oxo-2,3,4,5-tetrahydro-1H-1-benzazepin-3-yl]carbamate
Reaction equation
[Br:1]N1C(=O)CCC1=O.[O:9]=[C:10]1[C@@H:16]([NH:17][C:18](=[O:24])[O:19][C:20]([CH3:23])([CH3:22])[CH3:21])[CH2:15][CH2:14][C:13]2[CH:25]=[CH:26][CH:27]=[CH:28][C:12]=2[NH:11]1>CCOC(C)=O>[Br:1][C:26]1[CH:27]=[CH:28][C:12]2[NH:11][C:10](=[O:9])[C@@H:16]([NH:17][C:18](=[O:24])[O:19][C:20]([CH3:22])([CH3:23])[CH3:21])[CH2:15][CH2:14][C:13]=2[CH:25]=1Participants
4
Procedure
23.5 g of N-bromosuccinimide (136 mmol) are introduced, at AT, as 4 portions over 3 days, into a 2 l three-necked flask, with stirring and under an argon atmosphere, containing 1.5 l of EtOAc and 8.47 g of 2a (103.0 mmol). The medium is left stirring for an additional overnight period, and washed with 500 ml of HCl (0.5N), 500 ml of a saturated aqueous solution of NaHCO3 and 500 ml of water. The organic phase is dried over MgSO4, filtered and then evaporated to dryness. 38 g of brown foam are obtained. The product is purified by chromatography on a silica cartridge (600 g), elution being carried out with heptane/EtOAc (70/30). 20.46 g of expected product 10a (white solid) are recovered.