The imidazolidine ring in the title molecule, C17H15BrN2O2, is slightly ruffled [r.m.s. deviation = 0.0192 Å], while the attached phenyl rings at the C atom at the position between the amine and carbonyl centres are rotated well out of its mean plane [dihedral angles with the imidazolidine ring = 63.60 (8) and 76.4 (1)°]. In the crystal, a three-dimensional network features N—H...O and C—H...O hydrogen bonds together with C—H...π(ring) interactions.

In the title molecule, C17H16N2OS, the dihydroimidazolone ring is slightly puckered and the methylsulfanyl group is nearly coplanar with it. In the crystal, two sets of C—H...O hydrogen bonds form corrugated layers of molecules parallel to the ac plane. The layers pack with normal van der Waals contacts between them.

In the title molecule, C9H10ClNO2, the methoxy group lies very close to the plane of the phenyl ring while the acetamido group is twisted out of this plane by 28.87 (5)°. In the crystal, a three-dimensional structure is generated by N—H...O, C—H...O and C—H...Cl hydrogen bonds plus C—H...π(ring) interactions. A Hirshfeld surface analysis of the intermolecular interactions was performed and indicated that C...H/H...C interactions make the largest contribution to the surface area (33.4%).

The title molecule, C23H26N2O4S, adopts a cup-shaped conformation. In the crystal, layers lying parallel to the ab plane are formed by C—H...O hydrogen bonds and C—H...π(ring) interactions. The layers stack along the c-axis direction through normal van der Waals interactions.

The imidazolidine ring in the title molecule, C19H20N2O2, is slightly `ruffled'. In the crystal, a layer structure is generated by N—H...O and C—H...O hydrogen bonds plus C—H...π(ring) interactions.