title: Crystal structure of 3-(3-oxo-2,3,4,4a,5,6-hexa-hydro-benzo[h]cinnolin-2-yl)propionic acid.
abstract: The asymmetric unit of the title compound, C15H16N2O3, contains two independent mol-ecules, which present a different conformation of the carb-oxy-lic acid side chain [C-C-C-OH torsion angles = 65.3 (7) and -170.1 (5)°]. In both mol-ecules, the di-hydro-pyridazinone ring adopts a geometry inter-mediate between a twisted-boat and a half-chair conformation, while the central six-membered ring is almost in a half-boat conformation. In the crystal, mol-ecules are linked by O-H⋯Ok (k = ketone) hydrogen bonds, generating [01-1] chains. Aromatic π-π stacking contacts between the benzene and the di-hydro-pyridazinone rings [centroid-centroid distance [3.879 (9) Å] are also observed.
authors.affiliation: Department of Pharmaceutical Sciences, University of Milano, via L. Mangiagalli, 25, 20133-Milano, Italy.
authors.forename: Fiorella
authors.initials: F
authors.lastname: Meneghetti
authors.affiliation: Department of Pharmaceutical Sciences, University of Milano, via L. Mangiagalli, 25, 20133-Milano, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Masciocchi
authors.affiliation: Department of Pharmaceutical Sciences, University of Milano, via L. Mangiagalli, 25, 20133-Milano, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Gelain
authors.affiliation: Department of Pharmaceutical Sciences, University of Milano, via L. Mangiagalli, 25, 20133-Milano, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Villa
keywords: crystal structure; pyridazinone moiety; stat3 inhibitor