2-Nitro-1H-benzimidazole → 2-Isopropyl-1H-benzo[d]imidazol-5-amine

HRID 2186094Notes

Reaction equation

HRID 2186094 reaction equation
[N+](C1C=CC(N)=C(N)C=1)([O-])=O.[CH:12]([C:15]1[NH:16][C:17]2[CH:23]=[C:22]([N+:24]([O-])=O)[CH:21]=[CH:20][C:18]=2[N:19]=1)([CH3:14])[CH3:13].[N+](C1NC2C=CC=CC=2N=1)([O-])=O>C(O)(=O)C(C)C.CCOC(C)=O.CO.[Pd]>[CH:12]([C:15]1[NH:16][C:17]2[CH:23]=[C:22]([NH2:24])[CH:21]=[CH:20][C:18]=2[N:19]=1)([CH3:14])[CH3:13]

Participants

8

Reactant 3

HCID 972342-Nitro-1H-benzimidazoleHCID 6832022-Isopropyl-5-nitro-1H-benzo[d]imidazoleHCID 51117914-Nitro-1,2-phenylenediamine

Product 1

HCID 8207492-Isopropyl-1H-benzo[d]imidazol-5-amineYield 92%

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 887MethanolSolventHCID 6590Isobutyric AcidSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 4-nitro-1,2-phenylenediamine (0.9 g, 5.9 mmol) in 5 ml of isobutyric acid was stirred at reflux for 12 h. The reaction mixture was concentrated in vacuo to yield a dark brown residue, which was dissolved in 100 ml of EtOAc and washed with aqueous NaHCO3. Organic layer was dried over MgSO4 and concentrated in vacuo, yielding an oil which was characterized as 2-isopropyl-5-nitrobenzimidazole and subjected to a following reaction without further purification. The nitrobenzimidazole and 50 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 0.95 g (5.4 mmol, 92%) of the desired product.

Workup

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

Sources & evidence

ORD record
ord-f621ee388c9b4f87bc0d6ebc5ad288cf
Source dataset
uspto-grants-2002_06
Patent number
US06403626B1

Reaction notes

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