Cyanogen Bromide → 1H-Benzimidazole-5-carbonitrile, 2-amino-

HRID 552821Notes

Reaction equation

HRID 552821 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[NH2:10])[C:5]#[N:6].Br[C:12]#[N:13].[OH-].[Na+]>CO>[NH2:13][C:12]1[NH:1][C:2]2[CH:3]=[C:4]([C:5]#[N:6])[CH:7]=[CH:8][C:9]=2[N:10]=1

Participants

5

Reactant 3

HCID 10476Cyanogen BromideHCID 14798Sodium HydroxideHCID 7372853,4-Diaminobenzonitrile

Product 1

HCID 1134001H-Benzimidazole-5-carbonitrile, 2-amino-Yield 65.5%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
20 °C

Procedure

To a suspension of 3,4-diaminobenzonitrile (400 mg) in CH3OH (4 ml) was added BrCN (477 mg), followed by stirring at 20° C. for 14 hours. To the reaction mixture was added a 1M aqueous NaOH solution (0.117 ml), followed by concentration. To the residue was added chloroform:CH3OH=10:1 (10 ml), and the resulting insolubles were removed by filtration. The filtrate was concentrated, and the obtained residue was purified by silica gel column chromatography to obtain 2-amino-1H-benzimidazole-6-carbonitrile (311 mg) as pale orange color powders.

Workup

  1. concentrationfollowed by concentration
  2. additionTo the residue was added chloroform
  3. customCH3OH=10:1 (10 ml), and the resulting insolubles were removed by filtration
  4. concentrationThe filtrate was concentrated
  5. customthe obtained residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-4622d9c67dfd4cc6816f25a79164697c
Source dataset
uspto-grants-2011_05
Patent number
US07951825B2

Reaction notes

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