Synthesis and crystal structure of methyl 3-(3-hydroxy-3-phenylprop-2-enoyl)benzoate

The title compound, C17H14O4, was synthesized under mild conditions and characterized by various analytical techniques. Combined NMR and X-ray diffraction data show that the substance exists exclusively in the enol tautomeric form. An intramolecular center dot center dot center dot O=C-C=C-OH center dot center dot center dot hydrogen bond is present in the molecular structure. The analysis of the difference density map disclosed two adjacent positions of a disordered hydrogen atom taking part in this hydrogen bond, indicating the presence of two enol tautomers in the crystal. The enol molecules are assembled through numerous C-H center dot center dot center dot pi and pi-pi as well as weak C(aryl)-H center dot center dot center dot O interactions, thus forming a dense crystal packing. The obtained substance was also studied by UV-Vis spectroscopy and cyclic voltammetry.