Piperazine → tert-Butyl 4-(piperazin-1-yl)benzoate

HRID 856046Notes

Reaction equation

HRID 856046 reaction equation
Br[C:2]1[CH:14]=[CH:13][C:5]([C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7])=[CH:4][CH:3]=1.[NH:15]1[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1.CC(C)([O-])C.[Na+].C(OCC)(=O)C>C1(C)C=CC=CC=1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C1C=CC(P(C2C=CC3C(=CC=CC=3)C=2C2C3C(=CC=CC=3)C=CC=2P(C2C=CC=CC=2)C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.O>[N:15]1([C:2]2[CH:14]=[CH:13][C:5]([C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7])=[CH:4][CH:3]=2)[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1

Participants

9

Reactant 4

HCID 4837PiperazineHCID 8857Ethyl AcetateHCID 11334366Tert-butyl 4-bromobenzoateHCID 23676156Sodium t-butoxide

Product 1

HCID 23081213tert-Butyl 4-(piperazin-1-yl)benzoateYield 77%

Reagents, catalysts & solvents 4

HCID 167845palladium(II) acetateCatalystHCID 634876Binap, (A+-)-CatalystHCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

A mixture of tert-butyl 4-bromobenzoate (4.8 g, 18.8 mmol), piperazine (9.7 g, 0.11 mol), palladium acetate (85 mg, 0.38 mmol), (S)-(−)-BINAP (352 mg, 0.57 mmol), and sodium tert-butoxide (2.7 g, 28.2 mmol) in toluene (50 ml) was refluxed under a nitrogen atmosphere for 2 hours. Ethyl acetate and water were added to the reaction mixture and the insoluble substances were removed by filtration though Celite, and the filtrate was extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (methylene chloride/methanol=5/1) to afford tert-butyl 4-(piperazin-1-yl)benzoate (3.8 g, yield 77%) as a gray powder.

Workup

  1. temperaturewas refluxed under a nitrogen atmosphere for 2 hours
  2. customthe insoluble substances were removed by filtration though Celite
  3. extractionthe filtrate was extracted with ethyl acetate
  4. washThe extract was washed with brine
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated under reduced pressure
  8. customthe residue was purified by silica gel column chromatography (methylene chloride/methanol=5/1)

Sources & evidence

ORD record
ord-4d6c37131d724b9dbe6a06c83469b787
Source dataset
uspto-grants-2007_08
Patent number
US07262212B2

Reaction notes

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