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)° 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)°. 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⋯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⋯O hydrogen bonds. This results in the formation of a three-dimensional network structure.

The title compound, C 10 H 15 NO 2 , 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 À150.63 (11), À126.77 (13) and À138.76 (11) 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) . 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-HÁ Á ÁO 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-HÁ Á ÁO hydrogen bonds. This results in the formation of a three-dimensional network structure.   Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) x þ 1; y; z; (ii) Àx þ 1; Ày; Àz þ 1; (iii) x À 1; y; z; (iv) x þ 1 2 ; y; Àz þ 3 2 ; (v) Àx þ 3 2 ; y À 1 2 ; z.

Related literature
supplementary materials . E68, o3235-o3236 [doi:10.1107/S1600536812044091] 2-Ethyl-3-hydroxy-1-isopropyl-4-pyridone Pule P. Molokoane, M. Schutte and G. Steyl Comment 3-Hydroxypyridinones, which are derivatives of 3-hydroxypyranones, are known to have antimicrobial and antimalarial activity (Fassihi et al., 2009 andWeinberg, 1994). In addition to this, these compounds are non-toxic and they are approved for therapeutic use in some parts of the world (Galanello, 2007). Furthermore these organic compounds are metal ion chelators and they are used to prepare prodrugs with antioxidant characteristics and have brain targeting capabilities. These drugs have been suggested for the treatment of Alzheimer's disease and might possibly be more effective than treatments that just isolate metals (Scott et al., 2008).
As part of an ongoing study, O,O′-donor bidentate ligands are obtained by functionalizing commercially available 3-hydroxy-2-methylpyran-4-one (maltol) and 3-hydroxy-2-ethylpyran-4-one (ethyl maltol) to the respective 3-hydroxy-2methylpyrid-4-one and 3-hydroxy-2-ethylpyrid-4-one derivatives. The funtionalizations are performed in order to obtain an array of different electronic and steric properties imparted on the respective starting materials in order to study these effects. Coordination to copper(II) and designing a catalyst with a suitable support for oxidation and the kinetic study thereof are part of this study.
2-Ethyl-3-hydroxy-1-isopropylpyridinone crystallized in the orthorhombic Pbca space group with three molecules in the asymmetric unit. The average carbonyl distances (C=O) in the three molecules of 1.265 (4) Å are comparable to those of similar molecules that have been reported in the literature (Dobbin et al., 1993, Xiao et al., 1992, Burgess et al., 1993, Hider et al., 1990. These four structures differ only by the substituents on the N1 and C1 atoms and are reported as combinations of methyl and ethyl groups compared to ethyl (C1) and isopropyl (N1) for this structure. aromatic carbon C5B and a neighboring molecule's ketone oxygen (O1C). Finally, an intermolecular hydrogen interaction is observed between ethyl carbon C9B and a ketone oxygen (O1B).

Refinement
Aromatic H atoms were positioned geometrically and allowed to ride on their parent atoms, with U iso (H) = 1.2U eq (parent) of the parent atom with a C-H distance of 0.93 Å. The methyl and methene H atoms were placed in geometrically idealized positions and constrained to ride on its parent atoms with U iso (H) = 1.5U eq (C) and U iso (H) = 1.2U eq (C) and at a distance of 0.96 Å and 0.97 Å respectively. The methine hydrogen atoms were placed in geometrically idealized positions and constrained to ride on its parent atoms with U iso (H) = 1.2 U eq (C) and at a distance of 0.98 Å. Hydroxyl H atoms were placed from the electron density map and refined freely.
for molecule B and U iso (H) = 0.03682U eq (C) for molecule C.  Representation of the title compound, showing the numbering scheme and displacement ellipsoids (50% probability).

Computing details
Hydrogen atoms were omitted for clarity.    Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.