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

HRID 1267147Notes

Reaction equation

HRID 1267147 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-be747bbb86ea4097a1a9d9317a7388d8
Source dataset
uspto-grants-2003_04
Patent number
US06552042B2

Reaction notes

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