4-(4-Chloro-phen-yl)-1-(2-hydr-oxy-2,2-di-phenyl-acet-yl)thio-semicarbazide.

The asymmetric unit of the title compound, C(21)H(18)ClN(3)O(2)S, contains two mol-ecules in which the bond lengths and angles are almost identical. Intra-molecular N-H⋯S hydrogen bonds result in the formation of two five-membered rings. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers; these dimers are linked via inter-molecular O-H⋯S hydrogen bonds, leading to infinite corrugated layers parallel to the bc plane through R(2) (2)(16) ring motifs.