Benzyl 4-benzyl-3-oxopiperazine-1-carboxylate → 1-Benzylpiperazin-2-one

HRID 2109824Notes

Reaction equation

HRID 2109824 reaction equation
[CH2:1]([N:8]1[CH2:13][CH2:12][N:11](C(OCC2C=CC=CC=2)=O)[CH2:10][C:9]1=[O:24])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1>C(O)C.[Pd]>[CH2:1]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][C:9]1=[O:24])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 1

HCID 59750509Benzyl 4-benzyl-3-oxopiperazine-1-carboxylate

Product 1

HCID 15143031-Benzylpiperazin-2-one

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A mixture of benzyl 4-benzyl-3-oxopiperazine-1-carboxylate (4.7 g, 14.5 mmol) and 10% Pd/C (0.47 g) in ethanol (150 mL) was stirred under an atmosphere of hydrogen (1 atm) at room temperature overnight. The product mixture was filtered through a pad of Celite, and concentrated under vacuum to provide 1-benzylpiperazin-2-one. A portion of the resultant oil (1.06 g, 5.5 mmol) was treated with a mixture of N,N-diisopropylethylamine (1.46 mL, 8.3 mmol), DMAP (68 mg, 0.55 mmol), and acetic anhydride (0.73 mL, 7.8 mmol) in methylene chloride (30 mL) at 0° C. After stirring at room temperature overnight, the resultant mixture was concentrated and the residue was subjected to column chromatography on silica gel eluting with a 10-90 mixture of methanol and ethyl acetate. Collection and concentration of appropriate fractions provided the title piperazinone.

Workup

  1. filtrationThe product mixture was filtered through a pad of Celite
  2. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-ed8a2cc280244d0aa7726a0048071b14
Source dataset
uspto-grants-2009_04
Patent number
US07517532B2

Reaction notes

Loading…