1,4-二(羟基甲基)-2,5-哌嗪二酮

3,6-bis[(2-chlorophenyl)methylidene]piperazine-2,5-dione

2-[[2-[(2-bromo-3-methylbutanoyl)amino]acetyl]amino]acetic acid

1,4-dibenzylpiperazine-2,5-dione

哌嗪-2,3,5,6-四酮