Bromide ion → tert-Butyl piperazine-1-carboxylate

HRID 2297593Notes

Reaction equation

HRID 2297593 reaction equation
BrC1C=CC=CC=1OC1C=CC=CC=1Br.C([C:20]([N:22]1[CH2:27][CH2:26][NH:25][CH2:24][CH2:23]1)=[O:21])(C)(C)C.[CH3:28][C:29]([CH3:32])([O-:31])[CH3:30].[Na+].[Br-]>C1(C)C=CC=CC=1.C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1>[C:20]([N:22]1[CH2:27][CH2:26][NH:25][CH2:24][CH2:23]1)([O:31][C:29]([CH3:32])([CH3:30])[CH3:28])=[O:21]

Participants

7

Reactant 4

HCID 259Bromide ionHCID 27614081-(2,2-dimethylpropanoyl)piperazineHCID 3465096BDE-4HCID 23676156Sodium t-butoxide

Product 1

HCID 143452tert-Butyl piperazine-1-carboxylateYield 69.6%

Reagents, catalysts & solvents 2

HCID 634876Binap, (A+-)-CatalystHCID 1140TolueneSolvent

Procedure

Part B: To a solution of the bromophenyl ether of Part A (10.0 g, 41.1 mmol) in toluene (80 mL) was added 1-tert-butylcarbonylpiperazine (Lancaster, 9.2 g, 49.4 mmol) and sodium tert-butoxide (Fluka, 5.5 g, 57.5 mmol). The reaction stirred at ambient temperature for twenty minutes. BINAP (Aldrich, 0.8 g, 1.2 mmol) and tris(dibenzylideacetone)dipalladium (0) (Aldrich, 0.4 g, 0.4 mmol) were then added and the reaction was stirred at 80° C. until the bromide was exhausted. Work up comprised cooling the mixture to ambient temperature, filtering through a Celite® pad, and concentrating the filtrate. The resulting residue was purified on silica gel (ethyl acetate/hexanes) to afford the BOC-piperazine as a black oil (6.4 g, 44% yield). 1H NMR showed the desired compound.

Workup

  1. temperatureWork up comprised cooling the mixture to ambient temperature
  2. filtrationfiltering through a Celite® pad
  3. concentrationconcentrating the filtrate
  4. customThe resulting residue was purified on silica gel (ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-483c7b87898649c6a08840d0c16769be
Source dataset
uspto-grants-2002_12
Patent number
US06492367B1

Reaction notes

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