Triethylamine → Methyl 1,4-dibenzylpiperazine-2-carboxylate

HRID 2242812Notes

Reaction equation

HRID 2242812 reaction equation
[CH3:1][O:2][C:3](=[O:8])[CH:4](Br)[CH2:5]Br.CCN(CC)CC.[CH2:16]([NH:23][CH2:24][CH2:25][NH:26][CH2:27][C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]([CH:4]1[CH2:5][N:26]([CH2:27][C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)[CH2:25][CH2:24][N:23]1[CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:8]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 8793BenzathineHCID 95428Methyl 2,3-dibromopropionate

Product 1

HCID 10860321Methyl 1,4-dibenzylpiperazine-2-carboxylateYield 84.8%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To the preheated solution (50° C.) of 2,3-dibromo-propionic acid methyl ester in toluene (40 ml) and Et3N (5.80 ml, 41.6 mmol), was added N,N′-dibenzyl-ethane-1,2-diamine (4.90 ml, 20.8 mmol) dropwise. Resulting white slurry was heated to reflux to a clear solution and the solution was stirred at reflux overnight. After cooled to room temperature, the reaction mixture was extracted with 2N HCl (ca. 500 ml) and the extract was neutralized with 4N NaOH. The aqueous layer was extracted with EtOAc three times. The organic layer was washed with brine, dried over MgSO4, and concentrated to give 1,4-dibenzyl-piperazine-2-carboxylic acid methyl ester (5.73 g, 84.8%) as a colorless oil: HPLC-MS (ESI): Calcd for C20H24N2O2[M+H]+ 325, found: 325.

Workup

  1. customResulting white slurry
  2. temperaturewas heated
  3. temperatureto reflux to a clear solution
  4. temperatureat reflux overnight
  5. extractionthe reaction mixture was extracted with 2N HCl (ca. 500 ml)
  6. extractionThe aqueous layer was extracted with EtOAc three times
  7. washThe organic layer was washed with brine
  8. dry with materialdried over MgSO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-4638af4c55d54c88954281114b9314a0
Source dataset
uspto-grants-2010_03
Patent number
US07674797B2

Reaction notes

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