Bromide ion → tert-Butyl piperazine-1-carboxylate

HRID 842249Notes

Reaction equation

HRID 842249 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 min. 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-67ce7503580c432dae09953a015320cc
Source dataset
uspto-grants-2002_04
Patent number
US06372758B1

Reaction notes

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