Hydrochloric Acid → Thiophene, 2-(phenylmethyl)-

HRID 233128Notes

Reaction equation

HRID 233128 reaction equation
[Cl-].[Cl-].[Cl-].[Al+3].[C:5](Cl)(=O)[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.[S:14]1[CH:18]=[CH:17][CH:16]=[CH:15]1.Cl>ClC1C=CC=CC=1>[CH2:5]([C:15]1[S:14][CH:18]=[CH:17][CH:16]=1)[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric Acid2×HCID 7412Benzoyl chlorideHCID 8030ThiopheneHCID 6451240Aluminum(III) Chloride

Product 1

HCID 139391Thiophene, 2-(phenylmethyl)-

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent3×

Conditions

Temperature
0 °C

Procedure

27.2 g of 98.5% pure aluminium trichloride (sublimed) were suspended in 130 ml of chlorobenzene and cooled to 0° C. 28.7 g of benzoyl chloride were added dropwise while stirring and cooling over the course of 30 minutes, and the mixture was then stirred for 1 hour. Likewise at 0° C., a solution of 17.3 g of thiophene in 27 ml of chlorobenzene was added dropwise over the course of 30 minutes, and the mixture was stirred for 1 hour. Remaining hydrogen chloride was driven out by heating the mixture and stirring, finally under vacuum. The remaining solution was introduced over the course of 40 minutes into a solution of 12.7 g of dimethylamineborane in 70 ml of chlorobenzene while stirring at 70° C. The mixture was then stirred for 1 hour, cooled and discharged into a mixture of 200 g of ice and 50 g of concentrated aqueous hydrochloric acid while stirring. The aqueous phase was then separated off and extracted with chlorobenzene. The remaining organic phase was extracted by shaking with water. The organic phase and the extract from the aqueous phase were then combined, the solvent was removed therefrom by distillation, and 38.7 g of crude 2-benzylthiophene of 79.7% purity were obtained by distillation. This corresponds to 88.5% of theory. Redistillation resulted in 99.7% pure 2-benzylthiophene with a boiling point of 91° to 92° C./1.4 mbar.

Workup

  1. temperaturecooling over the course of 30 minutes
  2. stirringthe mixture was then stirred for 1 hour
  3. stirringthe mixture was stirred for 1 hour
  4. temperatureby heating the mixture
  5. stirringstirring, finally under vacuum
  6. stirringwhile stirring at 70° C
  7. stirringThe mixture was then stirred for 1 hour
  8. temperaturecooled
  9. stirringwhile stirring
  10. customThe aqueous phase was then separated off
  11. extractionextracted with chlorobenzene
  12. extractionThe remaining organic phase was extracted
  13. stirringby shaking with water
  14. extractionThe organic phase and the extract from the aqueous phase
  15. customthe solvent was removed
  16. distillationby distillation, and 38.7 g of crude 2-benzylthiophene of 79.7% purity
  17. customwere obtained by distillation
  18. distillationRedistillation
  19. customresulted in 99.7% pure 2-benzylthiophene with a boiling point of 91° to 92° C./1.4 mbar

Sources & evidence

ORD record
ord-5290fa2950cb4c32aba4f145d091498c
Source dataset
uspto-grants-1997_01
Patent number
US05591869

Reaction notes

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