3-Furaldehyde → 1-Cyclohexyl-2-(furan-3-yl)-1H-benzimidazole-5-carboxylic acid

HRID 1018240Notes

Reaction equation

HRID 1018240 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1C1(N)CCCCC1)[C:5]([O:7]CC)=[O:6].OOS([O-])=O.[K+].[O:26]1[CH:30]=[CH:29][C:28]([CH:31]=O)=[CH:27]1.[OH-].[Na+]>CN(C=O)C.O>[CH:2]1([N:1]2[C:12]3[CH:11]=[CH:10][C:4]([C:5]([OH:7])=[O:6])=[CH:3][C:2]=3[N:1]=[C:31]2[C:28]2[CH:29]=[CH:30][O:26][CH:27]=2)[CH2:3][CH2:4][CH2:10][CH2:11][CH2:12]1

Participants

7

Reactant 4

HCID 103513-FuraldehydeHCID 14798Sodium HydroxideHCID 22669240Ethyl 3-amino-4-(aminocyclohexyl)benzoateHCID 23707502Potassium hydroxy sulfite

Product 1

HCID 4911131-Cyclohexyl-2-(furan-3-yl)-1H-benzimidazole-5-carboxylic acidYield 170%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6228DimethylformamideSolvent

Procedure

Ethyl 3-amino-4-(aminocyclohexyl)benzoate (3.67 g, 13.99 mmol) was dissolved in DMF (10 mL) and water (1 mL). Oxone® (9. 8 mmol, 6.02 g) was added followed by 3-furaldehyde (1.44 g, 15 mmol). The mixture was stirred 45 min at room temperature. 4 N NaOH (20 mL) was added and the mixture stirred at 60° C. for 18 h. After cooling to room temperature, water (100 mL) was added and insoluble impurities removed by filtration through celite. AcOH was then added to precipitate the product as a beige solid. The precipitated carboxylic acid was collected by filtration, washed with water and dried to give the title compound as a beige solid (3.69 g, 85% yield).

Workup

  1. stirringthe mixture stirred at 60° C. for 18 h
  2. temperatureAfter cooling to room temperature
  3. custominsoluble impurities removed by filtration through celite
  4. additionAcOH was then added
  5. customto precipitate the product as a beige solid
  6. filtrationThe precipitated carboxylic acid was collected by filtration
  7. washwashed with water
  8. customdried

Sources & evidence

ORD record
ord-3382b8d2f7ce45e39f1cc49729b87ed5
Source dataset
uspto-grants-2002_11
Patent number
US06479508B1

Reaction notes

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