4-Benzyl-1-phenylpiperazin-2-one → 1-Phenylpiperazin-2-one

HRID 1696101Notes

Reaction equation

HRID 1696101 reaction equation
C([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[C:10](=[O:20])[CH2:9]1)C1C=CC=CC=1>[Pd].C(O)(=O)C>[C:14]1([N:11]2[CH2:12][CH2:13][NH:8][CH2:9][C:10]2=[O:20])[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

4

Reactant 1

HCID 114485104-Benzyl-1-phenylpiperazin-2-one

Product 1

HCID 138430241-Phenylpiperazin-2-oneYield 300.8%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolvent

Procedure

A mixture of 4-benzyl-1-phenylpiperazin-2-one (13.0 g, 48.8 mmol), 10% palladium on carbon (700 mg), and acetic acid (150 mL) was stirred under hydrogen at atmospheric pressure for 3 hours. The reaction was purged with nitrogen and filtered through a bed of celite. The filtrate was concentrated and the residue was purified via silica gel chromatography using 10% MeOH in CH2Cl2 to obtain the desired piperazinone as a white solid (8.3 g, 146.8 mmol, 96% yield). 1H NMR (400 MHz, CDCl3) δ 7.43-7.38 (m, 2H), 7.30-7.26 (m, 3H), 3.70-3.67 (m, 4H), 3.35 (s, 1H), 3.22 (t, J=5.5 Hz, 2H). LC/MS (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA)), m/z: M+1 obs=177.2; tR=0.44 min.

Workup

  1. customThe reaction was purged with nitrogen
  2. filtrationfiltered through a bed of celite
  3. concentrationThe filtrate was concentrated
  4. customthe residue was purified via silica gel chromatography

Sources & evidence

ORD record
ord-57ef152c5dcf45adbd84d962b6c3331c
Source dataset
uspto-grants-2012_04
Patent number
US08163720B2

Reaction notes

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