3-Ethyl-3-hydroxy-8-methoxyquinoline2,4(1H,3H)-dione monohydrate

In the title hydrate, C12H13NO4 center dot H2O, the piperidine ring that is fused to the benzene ring is in a sofa conformation with the chiral C atom lying 0.4084 (18) angstrom out of the plane of the nine fused-ring atoms. In the crystal, O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds link the organic molecules and water molecules into chains running along the b-axis direction. The chains are further connected into layers parallel to the bc plane by pi-pi interactions between inversion-related benzene rings [centroid-centroid distance = 3.8846 (9)].