Source of materialReagents and solvents used were of commercially available quality. Thesolution of 1-aminohydantoin hydrochloride (0.151 g, 1 mmol) in 1m Lo fw ater was added to as olution containing 2-hydroxybenzaldehyde (0.122 g, 1m mol) in 15 mL of absolute ethanol under heating and stirring. The mixture was then refluxed for 2h.Afterwards the mixture was cooled to room temperature and the resulting solution to stand in air. On slow evaporation of the solvent, colourless block-shaped crystals were obtained after 10 days. m.p.:2 76.9-278.3°C. Elemental analysis calcd. for C 10 H 9 N 3 O 3 :C,54.79; H, 4.14; N, 19.17; found: C, 54.73; H, 4.12; N, 19.19 %. IR (KBrpellet, cm -1 ): 3213s, 3095s, 2777m, 1780s, 1728s, 1622s, 1448s, 1381s, 1277s, 1215s, 1134s, 960m,856m, 748s, 698s, 582m.
Experimental detailsTheO1and N3 H-atom were locatedinadifferenceFourier map and refined with U iso (H) =1.2U eq .All other H-atoms were placed in calculated positionsand treated as riding:C-H =0.93or0.97 Å, with U iso (H) =1.2U eq (parentC-atom).
DiscussionThe important Schiff bases have awide range of applications in chemistry, biochemistry, medicine and technology [1,2]. And they were still regarded as one of the most potential group of organic compounds for facile preparations of metal containing hybrid materials. The ligands containing Oand Ndonor atoms, as analytical reagents,are increasing sincetheyenablesimpleand inexpensivedeterminationsofdifferent metal ions [3].Aspart of an ongoing study of Schiff bases containing Oand Ndonor atoms [4],t he title compound was synthesized. The X-ray diffraction analysis reveals that the compound adopts an E or trans configuration with respect to the C=N bond (N1=C7). In the molecule thereisanintramolecularO-H×××Nhydrogen bond involving the hydroxy substituent at the 2-positon of the benzene ring and the adjacentm ethyleneaminoNa tom( figure). Them olecule is almost planar, the dihedral angle between the benzene ring and imidazolidine-2,4-dione moiety 3.1(1)°, which is smaller than the dihedral angle of the similar compound (8.4(1)°, between the the naphthalene ring and imidazolidine-2,4-dione mean planes)f or its little steric hindrance [5]. In the crystal, pairs of N-H×××O i (i = -x,-y ,-z +1) hydrogen bonds link molecules into inversion dimers.
