3-Benzoyl-1-[4-(methyl-sulfan-yl)phen-yl]thio-urea.

The title compound, C15H14N2OS2, adopts a helix conformation. An intra-molecular N-H⋯O hydrogen bond leads to a six-membered pseudo-ring [r.m.s. deviation = 0.0212 Å, maximum deviation = 0.033 (1) Šfor the N atom bearing the benzoyl group] in the central unit. The benzene and (methyl-sulfan-yl)benzene ring [r.m.s = 0.0028 Šand largest deviation of 0.067 (3) Šfor the methyl-sulfanyl C atom] make dihedral angles of 31.76 (8) and 54.68 (6)°, respectively, with the pseudo-ring plane. The dihedral angle between the benzene rings is 85.71 (8)°. In the crystal, pairs of weak N-H⋯S inter-actions form inversion dimers and mediate a linear chain along [001].

rac-5-(1-Methyl-eth-yl)-2-sulfanylidene-imidazolidin-4-one.

In the title compound, C6H10N2OS, the 2-sulfanylideneimidazolidin-4-one fragment is essentially planar (r.m.s. deviation = 0.0033 Å). In the crystal, one amino group is involved in N-H⋯O hydrogen bonding, which links pairs of mol-ecules into inversion dimers, while the other amino group generates weak N-H⋯S hydrogen bonds, which link these dimers into chains in [10-1]. The chains are further aggregated into layers parallel to the ac plane through weak C-H⋯O inter-actions.