Similar names: 2-(5-Benzyl-3,6-dioxopiperazin-2-yl)acetic Acid; Aspartame Imp. A (EP); Diketopiperazine; 2-Piperazineacetic acid, 3,6-dioxo-5-(phenylmethyl)-, (2S,5S)- (9CI, ACI); (2S,5S)-3,6-Dioxo-5-(phenylmethyl)-2-piperazineacetic acid (ACI); 2-Piperazineacetic acid, 3,6-dioxo-5-(phenylmethyl)-, (2S-cis)- (ZCI); 2-Piperazineacetic acid, 5-benzyl-3,6-dioxo- (7CI, 8CI); Cycloaspartylphenylalanine; (2S,5S)-5-Benzyl-3,6-dioxo-2-piperazineacetic acid; 2-[(2S,5S)-5-Benzyl-3,6-dioxopiperazin-2-yl]acetic acid; (2S-cis)-5-Benzyl-3,6-dioxopiperazine-2-acetic acid