A monoclinic polymorph of N-eth-oxy-carbonyl-N'-(3-phenyl-1H-1,2,4-triazol-5-yl)thio-urea.

The title compound, C(12)H(13)N(5)O(2)S {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio-yl]carbamate}, is a monoclinic polymorph (space group P2(1)/c) which crystallizes with three similar independent mol-ecules in the asymmetric unit. The triazole ring makes dihedral angles of 6.6 (2), 8.4 (2) and 10.6 (2)° with the phenyl ring in the three independent molecules. The structure was previously reported [Dolzhenko et al. (2010a ▶). Acta Cryst., E46, o425] as a triclinic polymorph crystallizing in space group P. Mol-ecules in both polymorphs possess two S(6) rings generated by intra-molecular N-H⋯S and N-H⋯O hydrogen bonds, resulting in similar mol-ecular geometries. However, the two polymorphs differ in the crystal packing. In contrast to the dimers of the triclinic polymorph, mol-ecules of the monoclinic polymorph are connected by inter-molecular N-H⋯S and N-H⋯N hydrogen bonds, forming pseudosymmetric trimers arranged in sheets parallel to (302).