title: 2-[3,5-Dioxo-4-(pyridin-3-yl)piperazin-1-yl]acetic acid.
abstract: In the title compound, C(11)H(11)N(3)O(4), the 3,5-dioxopiperazine ring adopts an envelope conformation, with the N atom connecting to the -CH(2)COOH group on the flap. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds to produce a linear chain running along the c axis. π-π stacking is observed between parallel pyridine rings of adjacent mol-ecules, the centroid-centroid distance being 3.834 (2) Å.
authors.affiliation: Department of Chemistry, Yazd Branch, Islamic Azad University, PO Box 89195-155, Yazd,  Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Mosslemin