2-Ethyl-3-hydroxy-1-isopropyl-4-pyridone

The title compound, C10H15NO2, crystallized with three molecules in the asymmetric unit. These three molecules 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)degrees for molecules 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)degrees. The main difference between the three molecules lies in the way they are arranged in the solid-state structure. All three molecules form dimers that are connected through strong O-H center dot center dot center dot O hydrogen bonds with R-2(2) (10) graph-set motifs. The symmetry of the dimers formed does however differ between molecules. Molecules B connect with each other to form inversion dimers. Molecules A and C, on the other hand, form dimers with local twofold symmetry, but the two molecules are crystallographically distinct. The B and C molecules are linked to themselves and to each other via C-H center dot center dot center dot O hydrogen bonds. This results in the formation of a three-dimensional network structure.