5-(2,4-Dichlorophenoxymethyl)-1,3,4-thiadiazol-2-amine

The title compound, C9H7Cl2N3OS, was synthesized by the reaction of 2,4-dichlorophenoxyacetic acid and thiosemicarbazide. The dihedral angle between the thiadiazole and benzene rings is 21.5 (2)°. In the crystal, intermolecular N—H⋯N hydrogen bonding links the molecules into chains along the b axis.

The title compound, C 9 H 7 Cl 2 N 3 OS, was synthesized by the reaction of 2,4-dichlorophenoxyacetic acid and thiosemicarbazide. The dihedral angle between the thiadiazole and benzene rings is 21.5 (2) . In the crystal, intermolecular N-HÁ Á ÁN hydrogen bonding links the molecules into chains along the b axis.

S2. Experimental
2,4-Dichloro phenoxyacetic acid (2 mmol) and thiosemicarbazide (5 mmol) were mixed in a 25 ml flask, and kept in the oil bath at 363 K for 6 h. After cooling, the crude product (I) precipitated and was filtered. Pure compound (I) was obtained by crystallization from ethanol (20 ml). Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an acetone solution.

S3. Refinement
All H atoms were placed geometrically with C-H = 0.93-0.97 Å, N-H = 0.86 Å and included in the refinement in riding motion approximation with U iso (H) = 1.2U eq of the carrier atom.

Figure 1
A view of the molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level.

5-(2,4-Dichlorophenoxymethyl)-1,3,4-thiadiazol-2-amine
Crystal data C 9 H 7 Cl 2 N 3 OS M r = 276.14 Monoclinic, P2 1 /c Hall symbol: -P 2ybc a = 16.012 (3)  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.