1-(2,3,4-Trihydroxy-benzyl-idene)-4-ethyl-thio-semicarbazide

In the title mol-ecule, C(10)H(13)N(3)O(3)S, the thio-semicarbazide =N-NH-C(=S)-NH- fragment is twisted with respect to the aromatic ring [dihedral angle = 20.5 (1)°]. A weak N-H⋯S hydrogen bond [3.480 (1) Å] links two mol-ecules about a center of inversion to generate a ring. The hydr-oxy groups are engaged in inter-molecular hydrogen bonding; the O-H⋯O and O-H⋯S hydrogen bonds generate a layer motif.