Piperazine → 1-(4-Fluorophenyl)piperazine

HRID 583604Notes

Reaction equation

HRID 583604 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.Br[C:8]1[CH:13]=[CH:12][C:11]([F:14])=[CH:10][CH:9]=1>CC1C=CC=CC=1C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[F:14][C:11]1[CH:12]=[CH:13][C:8]([N:1]2[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]2)=[CH:9][CH:10]=1

Participants

5

Reactant 2

HCID 4837PiperazineHCID 99931-Bromo-4-fluorobenzene2×

Product 1

HCID 752601-(4-Fluorophenyl)piperazineYield 95%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 7237O-XyleneSolvent4×

Conditions

Temperature
120 °C

Procedure

A 200 ml Kjeldahl flask equipped with a cooling condenser and a thermometer was charged with a solution of 22.0 g of piperazine in 20 ml of o-xylene, a solution of 7.47 g of 1-bromo-4-fluorobenzene in 20 ml of o-xylene, and a solution of 5.66 g of NaOBut in 20 ml of o-xylene, and further with a solution of 48 mg of palladium acetate in 5 ml of o-xylene (the ratio of palladium atom/1-bromo-4-fluorobenzene=0.5% by mole). The flask was flushed with nitrogen for about 20 minutes while the content was stirred, and 0.25 ml of tri-tert.-butylphosphine was added. Then the mixture was heated to 120° C., and maintained at that temperature for 3 hours with stirring. After completion of the reaction, 80 ml of water was added to cool the reaction product. The mixture was introduced in a separatory funnel and the organic phase was separated. The lower aqueous phase was extracted with 40 ml of o-xylene. The organic phase was dried over sodium sulfate. Gas chromatographic analysis of the obtained product by the internal standard method revealed that the intended arylamine, i.e., N-(4-fluorophenyl)piperazine was obtained in a yield of 95% by mole.

Workup

  1. customA 200 ml Kjeldahl flask equipped with a cooling condenser
  2. customThe flask was flushed with nitrogen for about 20 minutes while the content
  3. addition0.25 ml of tri-tert.-butylphosphine was added
  4. temperaturemaintained at that temperature for 3 hours
  5. stirringwith stirring
  6. customAfter completion of the reaction, 80 ml of water
  7. additionwas added
  8. temperatureto cool the reaction product
  9. additionThe mixture was introduced in a separatory funnel
  10. customthe organic phase was separated
  11. extractionThe lower aqueous phase was extracted with 40 ml of o-xylene
  12. dry with materialThe organic phase was dried over sodium sulfate

Sources & evidence

ORD record
ord-e41a92bf260a4f5088695eabbe949036
Source dataset
uspto-grants-1999_07
Patent number
US05929281

Reaction notes

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