organic compounds
Diethyl 2-[(2-hydroxyanilino)methylidene]malonate, (I), and diethyl 2-[(4-hydroxyanilino)methylidene]malonate, (II), both C14H17NO5, crystallize in centrosymmetric orthorhombic and monoclinic crystal systems, respectively. Compound (I) resides on a crystallographic mirror plane and displays bifurcated intramolecular hydrogen bonding, as well as intermolecular hydrogen bonding due to the position of the hydroxy group. Compound (II) has a single intramolecular N—HO hydrogen bond. Infinite one-dimensional head-to-tail chains formed by O—HO hydrogen bonding are present in both structures. The molecular packing is mainly influenced by the intermolecular O—HO interactions. Additionally, C—HO interactions crosslinking the chains are found in (II).