5,6,7,8-Tetra-hydro-quinolin-8-one.

In the quinoline fused-ring system of the title compound, C(9)H(9)NO, the pyridine ring is planar to within 0.011†(3)†à , while the partially saturated cyclo-hexene ring adopts a sofa conformation with an asymmetry parameter ΔC(s)(C6) = 1.5†(4)°. There are no classical hydrogen bonds in the crystal structure. Mol-ecules form mol-ecular layers parallel to (100) with a distance between the layers of a/2 = 3.468†à .