5-({[(E)-Benzylideneamino]oxy}methyl)-1,3,4-thiadiazol-2-amine

In the molecule of the title compound, C10H10N4OS, the configuration about the C=N double bond is E. The dihedral angle between the thiadiazole and benzene rings is 81.1 (1)°. In the crystal, molecules are linked by N—H⋯N and C—H⋯O hydrogen bonds to form a two-dimensional network parallel with the bc plane.

In the molecule of the title compound, C 10 H 10 N 4 OS, the configuration about the C N double bond is E. The dihedral angle between the thiadiazole and benzene rings is 81.1 (1) . In the crystal, molecules are linked by N-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds to form a two-dimensional network parallel with the bc plane.

Experimental
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL. The thiadiazol moiety is the constituent of many biologically significant compounds. Thiadiazol derivatives showed diverse biological properties, such as antiparasitic activity (Ferrari et al., 2011), antioxidant properties and radioprotective effects (Cressier et al., 2009). As a part of our study on the synthesis of novel thiadiazol-containing compounds with good biological activities, we report here the crystal structure of the title compound, (I) (Fig. 1).
In the molecule, all bond lengths and angles are normal (Allen et al., 1987). The conformation of the N-H and the C=N bonds in the thiadiazol segment is similar to that observed in other thiadiazol compounds (Boechat et al., 2006). The dihedral angle between the thiadiazol and the benzene rings is 81.1 (1)°. The molecular structure is linked by intermolecular N-H···N and C-H···O hydrogen-bonds to form a two-dimensional network (Table 1, Fig. 2).

Experimental
To a mixture of aminothiourea (0.43 g, 4.7 mmol) and benzylideneaminooxyacetic acid (0.75 g, 4.3 mmol) phosphorus oxychloride (16.3 mmol) was added dropwise. The reaction mixture was heated at 353 K for 15 min, then cooled to room temperature and water (4.8 mL) was added slowly. After the addtion of water, the reaction mixture was first heated at 383 K for 4 h then cooled to room temperature. The pH of the reaction mixture was then adjusted to 8-9 by addition of 40% aqueous NaOH solution. The crude product was collected by filtration. Single crystals were obtained by evaporation of an ether solution of (I) at room temperature over a period of several days.

Refinement
The H atoms were placed in calculated positions (C-H = 0.93-0.97Å and N-H = 0.86 Å), and refined as riding with U iso (H) = 1.2U eq (C, N).

Figure 2
Crystal packing diagram of (I). Hydrogen bonds are shown as dashed lines. 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.