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

Participants

Reaction Steps

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.

Provenance & Evidence