2-Ethyl-3-hy-droxy-1-isopropyl-4-pyridone.

The title compound, C(10)H(15)NO(2), crystallized with three mol-ecules in the asymmetric unit. These three mol-ecules are quite similar except for slight differences in the torsion angles of the substituents on the ring. The isopropyl C-C-N-C torsion angles (towards the carbon next to the ethyl bound carbon), for example, are -150.63 (11), -126.77 (13) and -138.76 (11)° for mol-ecules A, B and C, respectively, and the C-C-C-N torsion angles involving the ethyl C atoms are 102.90 (13), 87.81 (14) and 86.47 (13)°. The main difference between the three mol-ecules lies in the way they are arranged in the solid-state structure. All three mol-ecules form dimers that are connected through strong O-H⋯O hydrogen bonds with R(2) (2)(10) graph-set motifs. The symmetry of the dimers formed does however differ between mol-ecules. Mol-ecules B connect with each other to form inversion dimers. Mol-ecules A and C, on the other hand, form dimers with local twofold symmetry, but the two mol-ecules are crystallographically distinct. The B and C molecules are linked to themselves and to each other via C-H⋯O hydrogen bonds. This results in the formation of a three-dimensional network structure.