2,5-Dimethoxybenzaldehyde thiosemicarbazone

In the title molecule, C10H13N3O2S, the dihedral angle between benzene and –N—C(=S)—N—N=C– planes is 9.20 (6)°. The two methoxy groups are coplanar with the benzene ring [C—O—C—C torsion angles of −2.31 (18) and −6.45 (17)°]. In the crystal structure, molecules are linked by intermolecular N—H⋯S, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network.


S1. Comment
Thiosemicarbazones are of great interest because of their profound biomedical properties (Beraldo et al., 2004).
Flexibility and bioactivity of these compounds arise due to the presence of amino group (-N═CH-) in addition to thioamino moieties present in the skeleton of the molecule. We have synthesized the title compound and its crystal structure is reported here.
In the crystal packing, the molecules are linked together by intermolecular N-H···S, N-H···O and C-H···O hydrogen bonds (Table 1) to form a three-dimensional network (Fig.2).

S2. Experimental
The title compound was synthesized by refluxing 2,5-dimethoxy benzaldehyde (0.075 mol) and thiosemicarbazone (0.05 mol) in methanol (100 ml) for 2 h. The solution was then allowed to cool, poured into a beaker containing water and stirred for 30 min. The product was separated by filtration and the crude sample obtained was recrystallized twice from hot methanol.

S3. Refinement
N-bound H atoms were located in a difference map and were refined with an N-H distance restraint of 0.86 (1)    The crystal packing of the title compound, viewed along the a axis. Dashed lines indicate hydrogen bonds. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 −0.01083 (