N-bromobutanimide → tert-butyl [(3S)-7-bromo-2-oxo-2,3,4,5-tetrahydro-1H-1-benzazepin-3-yl]carbamate

Participants

Reaction Steps

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.

Provenance & Evidence