Ammonium formate → 4-Bromo-1H-benzimidazole

HRID 475187Notes

Reaction equation

HRID 475187 reaction equation
[Br:1][C:2]1[C:3]([N+:9]([O-])=O)=[C:4]([NH2:8])[CH:5]=[CH:6][CH:7]=1.[CH:12]([O-])=O.[NH4+]>C(O)=O.[Pd]>[Br:1][C:2]1[C:3]2[N:9]=[CH:12][NH:8][C:4]=2[CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 218520723-Bromo-2-nitroaniline

Product 1

HCID 112525844-Bromo-1H-benzimidazoleYield 30.5%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 284Formic AcidSolvent

Conditions

Temperature
120 °C

Procedure

To a mixture of 3-bromo-2-nitrobenzenamine (4.7 g, 21.66 mmol) in formic acid (98%, 50 mL) was added 10% Pd/C and ammonium formate (13.6 g, 216.6 mmol) and the reaction mixture was stirred under nitrogen at 120° C. for 24 h. The catalyst was filtered, the filtrate was concentrated, the residue was dissolved in water (100 mL) and extracted with EtOAc (2×150 mL). The combined organic extracts were washed with water and brine, dried (Na2SO4), filtered and concentrated in vacuo to afford 1.3 g (30%) of crude 4-bromo-1H-benzo[d]imidazole (52) as dark brown solid: MS (ESI) m/z=197.1 [M+1]+.

Workup

  1. filtrationThe catalyst was filtered
  2. concentrationthe filtrate was concentrated
  3. dissolutionthe residue was dissolved in water (100 mL)
  4. extractionextracted with EtOAc (2×150 mL)
  5. washThe combined organic extracts were washed with water and brine
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-2014d393f39a43559259cebf79fafcdf
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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