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

HRID 1051908Notes

Reaction equation

HRID 1051908 reaction equation
[Cl:1][C:2]1[C:11]([Cl:12])=[CH:10][C:5]2[NH:6][C:7](=S)[NH:8][C:4]=2[CH:3]=1.[BrH:13].BrBr.[O-]S([O-])(=O)=O.[Na+].[Na+]>CO>[Br:13][C:7]1[NH:6][C:5]2[CH:10]=[C:11]([Cl:12])[C:2]([Cl:1])=[CH:3][C:4]=2[N:8]=1

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 24408BromineHCID 24436Sodium SulfateHCID 27742592-Mercapto-5,6-dichlorobenzimidazole

Product 1

HCID 4660172-bromo-5,6-dichloro-1H-benzimidazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

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.

Workup

  1. customNext MeOH was evaporated
  2. extractionThe aqueous layer was extracted with DCM
  3. customThe product was purified on silica gel

Sources & evidence

ORD record
ord-7826b272e63c44d194c3040cd280df48
Source dataset
uspto-grants-2016_07
Patent number
US09388192B2

Reaction notes

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