3-Ethyl-4-hy-droxy-8-meth-oxy-quinolin-2(1H)-one

3-Ethyl-3-hy-droxy-8-meth-oxy-quinoline-2,4(1H,3H)-dione monohydrate

In the title hydrate, C₁₂H₁₃NO₄·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) 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 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 π–π inter­actions between inversion-related benzene rings [centroid–centroid distance = 3.8846 (9) Å].