Hydrogen Bromide → 2-bromo-5,6-dichloro-1H-benzimidazole

Participants

Reaction Conditions

Reaction Steps

5,6-dichloro-2,3-dihydro-1H-1,3-benzodiazole-2-thione (2 mmol, 438 mg) was dissolved in MeOH (20 ml). The reaction mixture was cooled to 0° C. and hydrobromic acid (0.4 ml) was added, then bromine (8 mmol, 1.3 g) was added. The resulting mixture was stirred at RT overnight, then Na2SO4 was added. Next MeOH was evaporated. The aqueous layer was extracted with DCM. The product was purified on silica gel using EA/hex (1:1) to afford yellow solid (1 mmol, 260 mg), m/z 266.7; rt 2.8 min.

Provenance & Evidence