1,1'-Carbonyldiimidazole → 2-oxo-2,3-dihydro-1H-benzimidazole-5-carbonitrile

HRID 1533164Notes

Reaction equation

HRID 1533164 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[NH2:10])[C:5]#[N:6].[C:11](N1C=CN=C1)(N1C=CN=C1)=[O:12]>C1COCC1.CCOC(C)=O>[C:5]([C:4]1[CH:7]=[CH:8][C:9]2[NH:10][C:11](=[O:12])[NH:1][C:2]=2[CH:3]=1)#[N:6]

Participants

5

Reactant 2

HCID 682631,1'-CarbonyldiimidazoleHCID 7372853,4-Diaminobenzonitrile

Product 1

HCID 116439742-oxo-2,3-dihydro-1H-benzimidazole-5-carbonitrileYield 80%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

After 4-amino-3-nitrobenzonitrile (3.26 g, 20 mmol) was treated with hydrogen in MeOH (300 mL) in the presence of 5% palladium on active carbon (1 g) at room temperature for 16 hours, the reaction mixture was filtered and the filtrate was concentrated to give 3,4-diaminobenzonitrile (2.4 g, 90% yield). A solution of 3,4-diaminobenzonitrile (2 g, 15 mmol) in THF (100 mL) was treated with carbonyldiimidazole (CDI, 3.2 g, 19 mmol) at room temperature for 18 hours. The mixture was diluted with EtOAc (150 mL), washed with 1N HCl (30 mL) and brine, and dried over MgSO4. Filtration and concentration gave 5-cyanobenzimidazolinone (1.9 g, 80%). 1H NMR (CD3OD) δ 7.40 (dd, J=8.1 Hz, J=1.5 Hz, 1H), 7.34 (d, J=1.5 Hz, 1H), 7.15 (d, J=8.1 Hz, 1H); MS: 160.1 (M+H)+.

Workup

  1. washwashed with 1N HCl (30 mL) and brine
  2. dry with materialdried over MgSO4
  3. filtrationFiltration and concentration

Sources & evidence

ORD record
ord-bdcb120ec0584b158e4f57996aa5d2fd
Source dataset
uspto-grants-2001_03
Patent number
US06207697B1

Reaction notes

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