Synthesis, crystal structure and Hirshfeld surface analysis of 5,5-diphenyl-3-(prop-2-yn-1-yl)imidazolidine-2,4-dione

The new phenytoin analogue 5,5-diphenyl-3-(2-propyn-1-yl)imidazolidine-2,4-dione, C₁₈H₁₄N₂O₂ (<b>3</b>), was obtained through an alkyl-ation reaction with propargyl bromide <i>via</i> the phase-transfer catalysis method, and its structure was determined <i>via</i> single-crystal X-ray diffraction analysis. The asymmetric unit of <b>3</b> consists of two independent mol-ecules differing mainly in the orientation of the propynyl group. Each mol-ecule forms an inversion dimer through pairs of N2-H2⋯O2 hydrogen bonds. The crystal structure is further consolidated by C-H⋯O and C-H⋯π inter-actions. The contributions of the different inter-actions towards the crystal packing were further analysed using Hirshfeld surface and fingerprint plots, showing that the largest contribution comes from the H⋯H contacts (45%).