1-(4-Methoxyphenyl)imidazolidine-2,4-dione

In the title compound, C10H10N2O3, the dihedral angle between the benzene and imidazolidine rings is 6.0 (4)°, consistent with an essentially planar molecule. In the crystal, intermolecular N—H⋯O hydrogen bonding between centrosymmetrically related molecules leads to loosely associated dimeric aggregates. These are connected into a three-dimensional network by C—H⋯O interactions, as well as π–π interactions [centroid–centroid distances = 3.705 (3) and 3.622 (3) Å] between the imidazolidine and benzene rings.

In the title compound, C 10 H 10 N 2 O 3 , the dihedral angle between the benzene and imidazolidine rings is 6.0 (4) , consistent with an essentially planar molecule. In the crystal, intermolecular N-HÁ Á ÁO hydrogen bonding between centrosymmetrically related molecules leads to loosely associated dimeric aggregates. These are connected into a threedimensional network by C-HÁ Á ÁO interactions, as well as interactions [centroid-centroid distances = 3.705 (3) and 3.622 (3) Å ] between the imidazolidine and benzene rings.

Comment
During an investigation of new anti-diabetic drugs, we found that imidazolidinediones (IZD's) have good anti-diabetic activities. The crystal structure determination of the title compound, (I), was undertaken to investigate the relationship between structure and anti-diabetic activity.
In title compound, C 10 H 10 N 2 O 3 , bond lengths and angles are normal and in a good agreement with those reported previously (Gerdil, 1960). The dihedral angle between the benzene ring (C4-C9) and imidazolidine ring (C1-C3/N1/N2) is 6.0 (4) °. In the crystal packing, intermolecular N-H···O hydrogen bonding between centrosymmetrically related molecules lead to loosely associated dimeric aggregates, Table 1. These aggregates are connected into the 3-D crystal structure by C-H···O and π-π interactions, the latter occurring between the imidazolidine and benzene rings, Table 1.

Refinement
All C-bound H atoms were found on difference maps, but included in the final cycles of refinement using a riding model with C-H = 0.95-0.99 Å, and with U iso (H) = 1.2U eq (C) for aryl-and methylene-H atoms, and 1.5U eq (C) for the methyl H atoms. The N-H1 atom was refined freely.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > σ(F 2 ) is used only for calculating R-supplementary materials sup-3 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.