N-bromobutanimide → tert-butyl(2S,3S)-7-bromo-2-methyl-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a 0° C. solution of tert-butyl(2S,3S)-2-methyl-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamate (107.0 mg, 367 μmol) in DMF (2.45 ml) was added a solution of N-bromosuccinimide (68.6 mg, 386 μmol) in DMF (1.22 ml), dropwise over 5 min. The reaction was stirred at 0° C. for 30 min, then diluted with sat. aq. NH4Cl and extracted with EtOAc. The combined organic layers were washed with H2O, sat. aq. NaHCO3, and sat. aq. NaCl, dried over Na2SO4, and concentrated. The crude material was purified by flash chromatography to provide tert-butyl(2S,3S)-7-bromo-2-methyl-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamate (130 mg, 96%) as a white solid. MS m/z 392/394 (MNa)+.

Provenance & Evidence