Benzaldehyde → 1-Acetyl-3-benzylidene-2,5-piperazinedione

Participants

Reaction Steps

1,4-Diacetyl-2,5-piperazinedione (25.0 g, 126 mmol), which is compound (8) mentioned in Reference Example 1, was heated at 120°-130° C. in DMF (200 ml) with triethylamine (17.6 ml, 126 mmol) and benzaldehyde (13.0 ml, 126 mmol). After 4 h the mixture was cooled to room temperature and poured into EtOAc (1000 ml), and washed three times with brine. Any solid formed at this stage was filtered off. The filtrate was dried (MgSO4) and the solvent removed in vacuo. The residue was recrystallised from EtOAc:Hexane to give 11.78 g (38%) of the title compound as a yellow solid.

Provenance & Evidence