Imidazole → 4-(1H-Imidazol-1-yl)thiophene-2-carbaldehyde

HRID 2413981Notes

Reaction equation

HRID 2413981 reaction equation
Br[C:2]1[CH:3]=[C:4]([CH:7]=[O:8])[S:5][CH:6]=1.[NH:9]1[CH:13]=[CH:12][N:11]=[CH:10]1>[Cu].O>[N:9]1([C:2]2[CH:3]=[C:4]([CH:7]=[O:8])[S:5][CH:6]=2)[CH:13]=[CH:12][N:11]=[CH:10]1

Participants

5

Reactant 2

HCID 795ImidazoleHCID 877924-Bromothiophene-2-carbaldehyde

Product 1

HCID 133187124-(1H-Imidazol-1-yl)thiophene-2-carbaldehyde

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

In a three-necked-20-l-reaction bulb aquipped with a thermometer, a reflux cooler and a KPG-stirrer, 1.911 kg (10 mole) of 4-bromothiophen-2-aldehyde, 4.084 kg (60 mole) of imidazol of 99% purity and 0.065 kg (about 1 mole) of powderous copper metal are added to 10 l of water. The reaction mixture is stirred and boiled to reflux for 5 hours. After cooling the reaction mixture to 60° C., the reaction mixture is extracted several times with a total of 26 l of chloroform. The combined chloroform solutions are washed three times mit 15 l of water. The washed chloroform phase is mixed with 10 l of water and then brought to a pH of smaller than 1 by the addition of about 750 ml of 25% hydrochloric acid with vigorous stirring. The aqueous acidic phase is added with 30 l of chloroform at 40° C. Subsequently, about 600 g of NaHCO3 is added thereto slowly with vigorous stirring, until the aqueous phase reaches a pH larger than 7.5. In order to extract completely the precipitated product, the chloroform phase is separated and the aqueous phase is again extracted with 20 l of chloroform. The combined chloroform phases are evaporated to a final volume of about 4 l and is added to 9 l of petrol ether (b.p. 40° to 60° C.) with vigorous stirring. The resulting precipitate is filtered off with suction and is dried at 50° C.

Workup

  1. temperatureto reflux for 5 hours
  2. extractionthe reaction mixture is extracted several times with a total of 26 l of chloroform
  3. washThe combined chloroform solutions are washed three times
  4. additionThe washed chloroform phase is mixed with 10 l of water
  5. additionbrought to a pH of smaller than 1 by the addition of about 750 ml of 25% hydrochloric acid with vigorous stirring
  6. additionThe aqueous acidic phase is added with 30 l of chloroform at 40° C
  7. additionSubsequently, about 600 g of NaHCO3 is added
  8. extractionIn order to extract completely the precipitated product
  9. customthe chloroform phase is separated
  10. extractionthe aqueous phase is again extracted with 20 l of chloroform
  11. customThe combined chloroform phases are evaporated to a final volume of about 4 l
  12. additionis added to 9 l of petrol ether (b.p. 40° to 60° C.) with vigorous stirring
  13. filtrationThe resulting precipitate is filtered off with suction
  14. customis dried at 50° C.

Sources & evidence

ORD record
ord-a11fa47720714ee3b135d711de17ecec
Source dataset
uspto-grants-1988_01
Patent number
US04720550

Reaction notes

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