Aluminium lithium hydride → (R)-1,2-dibenzylpiperazine

HRID 581202Notes

Reaction equation

HRID 581202 reaction equation
[CH2:1]([C@H:8]1[N:13]([CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH2:12][CH2:11][NH:10][C:9]1=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>O1CCCC1>[CH2:14]([N:13]1[CH2:12][CH2:11][NH:10][CH2:9][C@H:8]1[CH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1)[C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1

Participants

4

Reactant 2

HCID 21226445Aluminium lithium hydride2×HCID 53922812(3R)-3,4-dibenzylpiperazin-2-one

Product 1

HCID 53338745(R)-1,2-dibenzylpiperazineYield 83.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of (3R)-3,4-dibenzylpiperazin-2-one (2.5 g; 9.0 mmol) in dry tetrahydrofuran (30 ml) was placed under an atmosphere of nitrogen and stirred on an ice-bath. Lithium aluminiumhydride (5.0 ml; 1.0M in tetrahydrofuran) was added dropwise during 15 minutes. The mixture was then heated at reflux temperature for 2 h and then allowed top cool. Another portion of lithium aluminiumhydride (4.0 ml; 1.0M in tetrahydrofuran) was added and the mixture was refluxed for 1 h. The mixture was allowed to cool and then quenched with water and a 4N sodium hydroxide solution. Ethyl acetate (50 ml) was added and the mixture was filtered. The solvent was evaporated in vacuo to give 2.0 g of (2R)-1,2-dibenzylpiperazine.

Workup

  1. temperatureThe mixture was then heated
  2. temperatureat reflux temperature for 2 h
  3. temperaturethe mixture was refluxed for 1 h
  4. temperatureto cool
  5. customquenched with water
  6. additionEthyl acetate (50 ml) was added
  7. filtrationthe mixture was filtered
  8. customThe solvent was evaporated in vacuo

Sources & evidence

ORD record
ord-4bcf95a6c12040d983f0f5451fbbb340
Source dataset
uspto-grants-1999_07
Patent number
US05919777

Reaction notes

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