Hydrogen Bromide → HCID 68771334, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 4-(7-amino-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)butanoate (23.0 g, 87.3 mmol) in acetic acid (250 mL) was added dropwise sodium nitrite (6.32 g, 91.7 mmol) in conc. sulfuric acid (80 mL) at 0° C., and the mixture was stirred at 0° C. for 20 min. The mixture was added dropwise to a solution of copper(I) bromide (50.1 g, 350 mmol) in conc. hydrobromic acid (150 mL) at 0° C., and the mixture was stirred at room temperature for 2 hr. The mixture was poured into aqueous sodium hydrogen carbonate, neutralized with potassium carbonate, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was washed with diisopropyl ether, recrystallized from ethyl acetate to give the title compound as a pale yellow crystal (5.79 g, 17.7 mmol, 20%).

Provenance & Evidence