title: 4-Hydr-oxy-6-[(4-hydr-oxy-1-oxo-1,2-dihydro-phthalazin-6-yl)carbon-yl]phthalazin-1(2H)-one.
abstract: In the crystal structure of the title compound, C(17)H(10)N(4)O(5), the mol-ecules lie on twofold axes (through the ketone bridge C and O atoms). The dihedral angle between the two phthalazine rings is 52.25 (1)°. In the crystal, inter-molecular N-H⋯O and O-H⋯O inter-actions link the mol-ecules.
authors.affiliation: Department of Chemistry, North University of China, Taiyuan, Shanxi 030051, People's Republic of China.
authors.forename: Rui-Sha
authors.initials: RS
authors.lastname: Zhou
authors.forename: Jiang-Feng
authors.initials: JF
authors.lastname: Song