title: 3-Ethyl-3-hy-droxy-8-meth-oxy-quinoline-2,4(1H,3H)-dione monohydrate.
abstract: In the title hydrate, C(12)H(13)NO(4)·H(2)O, the piperidine ring that is fused to the benzene ring is in a sofa conformation with the chiral C atom lying 0.4084 (18) Å out of the plane of the nine fused-ring atoms. In the crystal, O-H⋯O and N-H⋯O hydrogen bonds link the organic mol-ecules and water mol-ecules into chains running along the b-axis direction. The chains are further connected into layers parallel to the bc plane by π-π inter-actions between inversion-related benzene rings [centroid-centroid distance = 3.8846 (9) Å].
authors.affiliation: Department of Chemistry, Faculty of Technology, Tomas Bata University in Zlin, Zlin 76272,  Czech Republic.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kafka
authors.forename: Andrej
authors.initials: A
authors.lastname: Pevec
authors.forename: Karel
authors.initials: K
authors.lastname: Proisl
authors.forename: Roman
authors.initials: R
authors.lastname: Kimmel
authors.forename: Janez
authors.initials: J
authors.lastname: Košmrlj