Dioxopipérazine
The dioxopipérazines so called dicétopipérazines are a family of chemical compounds, including a core Pipérazine and two functions ketone, generally in opposition.
The dicétopipérazines can be the result of a cyclization of dipeptides (consituée molecule of two amino-acid ).
It is for example the case with the Aspartame which is the combination of the Aspartic acid (asp) and of the Phénylalanine (phe), the latter being esterified by methanol. During the degradation of the aspartame, the loss of methanol, releases the carboxylic acid function which can react with the function amine. A cycle with 6 atoms is formed then which is a dicétopipérazine. Indeed, the aspartame, in basic medium, loses one of the protons of its function amine, which allows, by an intramolecular reaction on one of the two carboxylic functions, of cycliser the molecule. The mechanism is of the addition type - elimination and occurs spontaneously with higher temperatures with 190°C. The dicétopipérazine for example is used in chromatography.