6-Nitro-2-(trifluoromethyl)-1H-benzimidazole → 5-Amino-2-(trifluoromethyl)benzimidazole

HRID 2186098

Reaction equation

HRID 2186098 reaction equation
[N+](C1C=CC(N)=C(N)C=1)([O-])=O.[F:12][C:13]([F:27])([F:26])[C:14]1[NH:15][C:16]2[CH:22]=[C:21]([N+:23]([O-])=O)[CH:20]=[CH:19][C:17]=2[N:18]=1.[N+](C1NC2C=CC=CC=2N=1)([O-])=O>FC(F)(F)C(O)=O.CCOC(C)=O.CO.[Pd]>[F:27][C:13]([F:12])([F:26])[C:14]1[NH:15][C:16]2[CH:22]=[C:21]([NH2:23])[CH:20]=[CH:19][C:17]=2[N:18]=1

Participants

8

Reactant 3

HCID 675956-Nitro-2-(trifluoromethyl)-1H-benzimidazoleHCID 972342-Nitro-1H-benzimidazoleHCID 51117914-Nitro-1,2-phenylenediamine

Product 1

HCID 193455-Amino-2-(trifluoromethyl)benzimidazoleYield 80%

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 887MethanolSolventHCID 6422Trifluoroacetic acidSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 4-nitro-1,2-phenylenediamine (3.0 g, 20 mmol) in 15 ml of trifluoroacetic acid was stirred at reflux for 12 h. The reaction mixture was concentrated in vacuo to yield a oily residue, which was dissolved in 100 ml of EtOAc and washed with aqueous NaHCO3. The organic layer was dried over MgSO4 and concentrated in vacuo to provide an oil which was characterized as 2-trifluromethyl-5-nitrobenzimidazole and subjected to the following reaction without further purification. The nitrobenzimidazole and 500 mg of 10% Pd-C were dissolved in 100 ml of MeOH and stirred for 12 h under H2. The reaction mixture was filtered and concentrated in vacuo, yielding 3.2 g (16 mmol, 80%) of the desired product.

Workup

  1. temperatureat reflux for 12 h
  2. concentrationThe reaction mixture was concentrated in vacuo
  3. customto yield a oily residue, which
  4. washwashed with aqueous NaHCO3
  5. dry with materialThe organic layer was dried over MgSO4
  6. concentrationconcentrated in vacuo
  7. customto provide an oil which
  8. customsubjected to the following reaction without further purification
  9. filtrationThe reaction mixture was filtered
  10. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-482a8f900a594efcb7d2eb9e7b91175a
Source dataset
uspto-grants-2002_06
Patent number
US06403626B1

Linked notes

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