Crystal structure of 3-(3-oxo-2,3,4,4a,5,6-hexa­hydro­benzo[h]cinnolin-2-yl)propionic acid

The asymmetric unit of the title compound, C(15)H(16)N(2)O(3), contains two independent mol­ecules, which present a different conformation of the carb­oxy­lic acid side chain [C—C—C—OH torsion angles = 65.3 (7) and −170.1 (5)°]. In both mol­ecules, the di­hydro­pyridazinone ring adopts a geometry inter­mediate 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, mol­ecules are linked by O—H⋯O(k) (k = ketone) hydrogen bonds, generating [01-1] chains. Aromatic π–π stacking contacts between the benzene and the di­hydro­pyridazinone rings [centroid–centroid distance [3.879 (9) Å] are also observed.