1,3-Bis(2-oxopropyl)thymine

In the title compound, C11H14N2O4, the two 2-oxopropyl groups are nearly perpendicular to the planar thymine unit. One methyl group of the oxopropyl substituent is disordered. In the crystal, C—H⋯O interactions help to connect the molecules into (001) layers.


Structure description
Nucleoside analogs play an important role in combating viral diseases and neoplasms; this is demonstrated by the pharmacological success of drugs such as Zidovudine, Stavudine, Lamivudine, and around 20 others belonging to this group of compounds (Adamska et al., 2016;Krim et al., 2012;Negró n-Silva et al., 2013;Thakur et al., 2014). We performed the transformation of N 1 ,N 3 -bispropargyl thymine and uracyl, which furnished N 1 ,N 3 -bis-(2-oxopro-1-yl) derivatives; these compounds offer ample possibilities of further functionalization via C or O alkylation of their enolates, or via reductive amination, among others.
In the title compound ( Fig. 1), the thymine unit is nearly planar, with the largest deviation from the mean plane being less than 0.03 Å . The two essentially planar 2-oxopropyl substituents are almost perpendicular to the thymine unit; the dihedral angles between the mean plane of the six-membered ring and those of the 2-oxopropyl fragments with atoms C1 and C7 are 77.96 (1) and 82.92 (1) , respectively. Rotational disorder was observed for the C1 methyl group of the 2-oxopropyl substituent.
There are no usual hydrogen bonds in this structure. Attractive C-HÁ Á ÁO interactions (Table 1), involving all oxygen atoms of the molecule, help to organize the molecules in a layer parallel to the (001) plane. These layers are packed in the three-dimensional crystal by van der Waals forces, mainly between hydrogen atoms (Fig. 2). data reports

Figure 1
Numbering scheme for the title compound, shown with 50% probability displacement ellipsoids. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.21 e Å −3 Δρ min = −0.18 e Å −3 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.

data-2
IUCrData (2020). 5, x200257 Refinement. Methylene hydrogen atoms are refined with riding coordinates and with U iso (H) = 1.2 U iso (C); methyl hydrogen atoms are refined as rotating idealized methyl groups and with U iso (H) = 1.5 U iso (C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (