Hydrochloric Acid → 5-bromo-2,7-dimethyl-1H-1,3-benzodiazole

HRID 1880404Notes

Reaction equation

HRID 1880404 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([NH2:8])[C:5]([NH2:9])=[C:4]([CH3:10])[CH:3]=1.Cl.[CH3:12][C:13](=O)CC(=O)C.C([O-])(O)=O.[Na+]>CCO>[Br:1][C:2]1[CH:3]=[C:4]([CH3:10])[C:5]2[N:9]=[C:12]([CH3:13])[NH:8][C:6]=2[CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 31261AcetylacetoneHCID 516892Sodium BicarbonateHCID 15163975-Bromo-3-methylbenzene-1,2-diamine

Product 1

HCID 669204475-bromo-2,7-dimethyl-1H-1,3-benzodiazoleYield 96.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 5-bromo-3-methylbenzene-1,2-diamine (201 mg, 1.00 mmol) in EtOH (15 mL) was added 5 N HCl (4 mL). The mixture was heated at reflux before addition of 2,4-pentanedione (200 mg, 0.21 mL, 2.0 mmol). Heating was continued for 45 minutes before analysis indicated the reaction was complete. The reaction was cooled to room temperature, neutralized with saturated aqueous NaHCO3 and extracted with CHCl3. The organic layer was washed with saturated aqueous NaCl, dried over MgSO4, filtered, concentrated and dried to afford 6-bromo-2,4-dimethyl-1H-benzimidazole (217 mg, 96%).

Workup

  1. temperatureThe mixture was heated
  2. temperatureHeating
  3. extractionextracted with CHCl3
  4. washThe organic layer was washed with saturated aqueous NaCl
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customdried

Sources & evidence

ORD record
ord-004b59d06493464492fd01306398f30c
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

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