N-bromobutanimide → 3-bromo-9H-imidazo[1,2-d]pyrido[2,3-b][1,4]benzodiazepine

Participants

Reaction Steps

To a suspension of 9H-imidazo[1,2-d]pyrido[2,3-b][1,4]benzodiazepine (1.19 g, 5.1 mmol) in THF (60 mL) was slowly added N-bromosuccinimide (0.90 g, 4.3 mmol) at 0° C. The reaction mixture was stirred at room temperature for 2 hours, quenched with sat.NaHCO3, extracted with ethyl acetate. The organic layers were washed with brine and dried over anhydrous Na2SO4. After filtration the solvent was removed under reduced pressure. The crude product was purified by silica gel chromatography (hexane/ethyl acetate) to give a pale yellow solid (96%). 1H NMR (DMSO-d6) 400 MHz δ: 8.58 (s, 1H), 8.26 (dd, J=4.9, 1.4 Hz, 1H), 7.94 (dd, J=8.0, 1.7 Hz, 1H), 7.74 (dd, J=7.7, 1.4 Hz, 1H), 7.43 (s, 1H), 7.34 (td, J=7.7, 1.9 Hz, 1H), 7.25-7.21 (m, 2H), 7.08 (td, J=7.5, 1.2 Hz, 1H); LC/MS [M+H]: 314.

Provenance & Evidence