Benzimidazole → HCID 67351942, compound

HRID 1676021Notes

Reaction equation

HRID 1676021 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][CH:2]=1.[CH2:10]([C:12]1[CH:17]=[CH:16][C:15]([C:18]#[C:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])=[CH:14][CH:13]=1)[CH3:11].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[N:1]1([C:18]([C:15]2[CH:16]=[CH:17][C:12]([CH2:10][CH3:11])=[CH:13][CH:14]=2)=[CH:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[CH:2]1

Participants

5

Reactant 3

HCID 5798BenzimidazoleHCID 11430Potassium CarbonateHCID 67355299HCID 67355299, compound

Product 1

HCID 67351942HCID 67351942, compound

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of benzimidazole (118 mg, 1.00 mmol) in DMF (3 mL) was added ethyl 3-(4-ethylphenyl)-2-propynoate (202 mg, 1.00 mmol) and potassium carbonate (152 mg, 1.10 mmol). This suspension was heated to 100° C. for 48 hours, then cooled to room temperature, and evaporated in vacuo. The residue was partitioned between water and dichloromethane, and the separated aqueous layer extracted with dichloromethane. The combined organic layers were dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo. The residue was purified by flash column chromatography on silica gel, eluting with a mixture of dichloromethane and methanol (96:4) to afford (in order of elution), ethyl (2Z)-3-(1H-benzimidazol-1-yl)-3-(4-ethylphenyl)-2-propenoate, mixed fractions, and ethyl (2E)-3-(1H-benzimidazol-1-yl)-3-(4-ethylphenyl)-2-propenoate.

Workup

  1. temperaturecooled to room temperature
  2. customevaporated in vacuo
  3. customThe residue was partitioned between water and dichloromethane
  4. extractionthe separated aqueous layer extracted with dichloromethane
  5. dry with materialThe combined organic layers were dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customThe residue was purified by flash column chromatography on silica gel
  9. washeluting with a mixture of dichloromethane and methanol (96:4)
  10. customto afford
  11. wash(in order of elution), ethyl (2Z)-3-(1H-benzimidazol-1-yl)-3-(4-ethylphenyl)-2-propenoate
  12. additionmixed fractions, and ethyl (2E)-3-(1H-benzimidazol-1-yl)-3-(4-ethylphenyl)-2-propenoate

Sources & evidence

ORD record
ord-60aee5917fe04ece842761384ea8809e
Source dataset
uspto-grants-2011_08
Patent number
US08003806B2

Reaction notes

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