Benzaldehyde → (Z)-1-Acetyl-3-benzylidenepiperazine-2,5-dione

Participants

Reaction Steps

1,4-Diacetyl-2,5-piperazinedione (25.0 g, 126 mmol), which is compound (8) mentioned in Reference Example 3, 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.

Provenance & Evidence