4-Nitroaniline → N-(4-nitrophenyl)-1H-benzimidazol-2-amine

HRID 1429880Notes

Reaction equation

HRID 1429880 reaction equation
Cl[C:2]1[NH:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.[N+:11]([C:14]1[CH:20]=[CH:19][C:17]([NH2:18])=[CH:16][CH:15]=1)([O-:13])=[O:12]>CN1C(=O)CCC1.C(OCC)(=O)C>[N+:11]([C:14]1[CH:20]=[CH:19][C:17]([NH:18][C:2]2[NH:3][C:4]3[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=3[N:6]=2)=[CH:16][CH:15]=1)([O-:13])=[O:12]

Participants

5

Reactant 2

HCID 74754-NitroanilineHCID 785722-Chlorobenzimidazole

Product 1

HCID 5219340N-(4-nitrophenyl)-1H-benzimidazol-2-amineYield 24%

Reagents, catalysts & solvents 2

HCID 8857Ethyl AcetateSolventHCID 13387N-methyl-2-pyrrolidoneSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of 2-chlorobenzimidazole (10.0 g) and 4-nitroaniline (9.05 g) in NMP (130 mL) was stirred at 120° C. for 3 days. After this time, the reaction mixture was cooled to ambient temperature, diluted with ethyl acetate (750 mL) and washed with water (750 mL). The aqueous layer was extracted with ethyl acetate (750 mL) and the combined organic extracts were washed with water (3×750 mL) then brine (750 mL), dried over sodium sulfate, and filtered and the filtrate was concentrated under reduced pressure. The residue obtained was triturated with 1:1 ethyl acetate/heptane (200 mL) and the solid that formed was collected by filtration to afford N-(4-nitrophenyl)-1H-benzimidazol-2-amine (4.00 g) as an orange solid.

Workup

  1. temperatureAfter this time, the reaction mixture was cooled to ambient temperature
  2. washwashed with water (750 mL)
  3. extractionThe aqueous layer was extracted with ethyl acetate (750 mL)
  4. washthe combined organic extracts were washed with water (3×750 mL)
  5. dry with materialbrine (750 mL), dried over sodium sulfate
  6. filtrationfiltered
  7. concentrationthe filtrate was concentrated under reduced pressure
  8. customThe residue obtained
  9. customwas triturated with 1:1 ethyl acetate/heptane (200 mL)
  10. customthe solid that formed
  11. filtrationwas collected by filtration

Sources & evidence

ORD record
ord-a263c4181a854be588e4e5329ca0e3a5
Source dataset
uspto-grants-2015_01
Patent number
US08940758B2

Reaction notes

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