3-{(E)-[4-(4-Hydroxy-3-methoxyphenyl)butan-2-ylidene]amino}-1-phenylurea: crystal structure and Hirshfeld surface analysis

Abstract

Two independent molecules (A and B) comprise the asymmetric unit of the title compound, C18H21N3O3. The urea moiety is disubstituted with one amine being linked to a phenyl ring, which is twisted out of the plane of the CN2O urea core [dihedral angles = 25.57 (11) (A) and 29.13 (10)° (B)]. The second amine is connected to an imine (E conformation), which is linked in turn to an ethane bridge that links a disubstituted benzene ring. Intramolecular amine-N—H...N(imine) and hydroxyl-O—H...O(methoxy) hydrogen bonds close S(5) loops in each case. The molecules have twisted conformations with the dihedral angles between the outer rings being 38.64 (81) (A) and 48.55 (7)° (B). In the crystal, amide-N—H...O(amide) hydrogen bonds link the molecules A and B via an eight-membered {...HNCO}2 synthon. Further associations between molecules, leading to supramolecular layers in the ac plane, are hydrogen bonds of the type hydroxyl-O—H...N(imine) and phenylamine-N—H...O(methoxy). Connections between layers, leading to a three-dimensional architecture, comprise benzene-C—H...O(hydroxy) interactions. A detailed analysis of the calculated Hirshfeld surfaces shows molecules A and B participate in very similar intermolecular interactions and that any variations relate to conformational differences between the molecules.

Keywords

• crystal structure
• urea derivative
• hydrogen bonding
• Hirshfeld surface analysis