Potassium Carbonate → Benzimidazole

HRID 1033219Notes

Reaction equation

HRID 1033219 reaction equation
C([C:3]1[NH:4][C:5]2[CH:11]=[CH:10][CH:9]=[CH:8][C:6]=2[N:7]=1)#N.C(=O)([O-])[O-].[K+].[K+].CN(C)S(Cl)(=O)=O>C(#N)C>[N:4]1[C:5]2[CH:11]=[CH:10][CH:9]=[CH:8][C:6]=2[NH:7][CH:3]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 83372Dimethylsulphamoyl chlorideHCID 8438581H-benzimidazole-2-carbonitrile2×

Product 1

HCID 5798Benzimidazole

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

1.8 Grams of a 2-cyanobenzimidazole compound [compound (iii)] of the formula (II) in which X is Br and Z is OCF2CFHO was dissolved in 70 ml of acetonitrile. 1.5 Grams of potassium carbonate was added thereto. The resulting mixture was heated under reflux for 20 minutes. Thereafter, 1.2 g of dimethylsulfamoyl chloride was added thereto. Refluxing was continued for 1 hour with heating. The reaction solution was poured into ice water and extracted with ethyl acetate. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated. Column chromatographying the resulting residue on silica gel with chloroform as an eluent and recrystallizing it from hexane/ethyl acetate gave 1.18 g of a benzimidazole derivative [present compound (3)]of the formula (I) in which X is Br, Z is OCF2CFHO, R is CN and Q is N(CH3)2.

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureunder reflux for 20 minutes
  3. temperatureRefluxing
  4. temperaturewith heating
  5. extractionextracted with ethyl acetate
  6. washThe organic layer was washed with water
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationconcentrated
  9. customrecrystallizing it from hexane/ethyl acetate

Sources & evidence

ORD record
ord-0c1360c6d04f410996aa38860f8ee690
Source dataset
uspto-grants-1994_05
Patent number
US05310747

Reaction notes

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