3'-[Hy-droxy(4-oxo-4H-chromen-3-yl)meth-yl]-2-oxospiro-[indoline-3,2'-pyrrolidine]-3'-carbonitrile.

In the title compound, C(23)H(19)N(3)O(4), the pyran ring adopts a half-chair conformation, while the pyrrolidine (with a C atom as the flap atom) and the five-membered ring in the indoline (with a C atom as the flap atom) ring system adopt slight envelope conformations. The pyrrolidine ring makes dihedral angles of 83.3 (1) and 60.4 (1)° with the mean plane through all non-H atoms of the indoline and chromene ring systems, respectively. In the crystal, mol-ecules are connected by two unique N-H⋯O and O-H⋯O hydrogen-bonding inter-actions, which form centrosymmetric patterns described by graph-set motifs R(2) (2)(18) and R(2) (2)(14). These two motifs combine to form a hydrogen-bonded chain which propagates in the a-axis direction. The crystal structure is also stablized by C-H⋯O inter-actions and by aromatic π-π stacking inter-actions between the pyran and benzene rings of neighbouring mol-ecules [centroid-centroid distance = 3.755 (1) Šand slippage = 1.371 (2) Å].

(E)-Methyl 3-(4-ethyl-phen-yl)-2-{2-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy-meth-yl}acrylate.

In the title compound, C(20)H(21)NO(4), the two benzene rings are almost perpendicular to each other, making a dihedral angle of 86.1 (7)°. The hy-droxy-ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane of the hy-droxy-ethanimine [C=N-OH] group being 0.011 (1) Šfor the O atom. An intra-molecular C-H⋯O hydrogen bond occurs. The mol-ecules are linked into cyclic centrosymmetric R(2) (2)(6) dimers via O-H⋯N hydrogen bonds. Inter-molecular C-H⋯O hydrogen bonds link the mol-ecules, forming a C(8) chain along the a axis. The crystal packing is further stabilized by C-H⋯π inter-actions.

1-Benzyl-2,5-diphenyl-3-tosylimidazol-idin-4-one.

In the title compound, C(29)H(26)N(2)O(3)S, the central imidazolidine ring adopts an envelope conformation with the N atom bearing the benzyl ring at the flap. The S atom has distorted tetra-hedral geometry. The benzyl and tosyl rings are oriented at a dihedral angle of 52.1 (1)°. The phenyl rings connected to the imidazolidine ring form a dihedral angle of 28.7 (1)°.

2-(4-Chloro-phen-yl)-5-(cyclo-hex-1-en-1-yl)-3-(4-methyl-phenyl-sulfon-yl)-1-phenyl-imidazolidin-4-one.

In the title compound, C(28)H(27)ClN(2)O(3)S, the central imidazolidine ring adopts an envelope conformation with the C atom bearing the chloro-phenyl ring at the flap. The geometry around the S atom is distorted tetra-hedral. Three methyl-ene groups of the cyclo-hexene ring are disordered over two sets of sites [site occupancies = 0.562 (10) and 0.438 (10)]. The crystal packing is stabilized by C-H⋯π inter-actions.

(E)-Methyl 3-(4-chloro-phen-yl)-2-{2-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy-meth-yl}acrylate.

In the title compound, C(18)H(16)ClNO(4), the dihedral angle between the mean planes through the aromatic rings is 83.8 (8)°. The hy-droxy-ethanimine group is essentially coplanar with the ring to which it is attached [O-N-C-C torsion angle = -177.96 (13)°]. The mol-ecules are linked into centrosymmetric R(2) (2)(6) dimers via O-H⋯N hydrogen bonds. The crystal packing is further stabilized by C-H⋯O inter-actions.