1-(2H-1,3-Benzodioxol-5-yl)ethanone thiosemicarbazone

In the title compound, C10H11N3O2S, the 1,3-benzodioxole and hydrazinecarbothioamide fragments are nearly planar [(mean deviations from planarity for non-H atoms of 0.0325 (12) Å and 0.0707 (10) Å, respectively] and subtend a dihedral angle of 29.06 (5)°. In the crystal, molecules are linked by pairs of almost linear N—H⋯S hydrogen bonds, forming inversion dimers. These dimers are additionally connected by weaker and strongly bent N—H⋯S interactions into chains along [101]. There is one additional weak N—H⋯O contact which, if considered as an interaction, leads to the formation of a three-dimensional network.

In the title compound, C 10 H 11 N 3 O 2 S, the 1,3-benzodioxole and hydrazinecarbothioamide fragments are nearly planar [(mean deviations from planarity for non-H atoms of 0.0325 (12) Å and 0.0707 (10) Å , respectively] and subtend a dihedral angle of 29.06 (5) . In the crystal, molecules are linked by pairs of almost linear N-HÁ Á ÁS hydrogen bonds, forming inversion dimers. These dimers are additionally connected by weaker and strongly bent N-HÁ Á ÁS interactions into chains along [101]. There is one additional weak N-HÁ Á ÁO contact which, if considered as an interaction, leads to the formation of a three-dimensional network.
In the crystal structure of the title compound, C 10 H 11 N 3 O 2 S, the molecules are twisted and consists of two nearly planar parts, a benzo[1,3]dioxole fragment and a hydrazinecarbothioamide fragment (mean deviations from planarity for non-H atoms 0.0325 (12) Å and 0.0707 (10) Å, respectively), which subtend a dihedral angle of 29.06 (5)° (Fig. 1). The molecule shows an E conformation for the atoms about the N3-N2 and N2-C1 bonds, which is also observed in the crystal structures of other thiosemicarbazone derivatives (de Oliveira et al., 2012).
In the crystal structure the molecules are linked by pairs of N-H···S hydrogen bonds into inversion related dimers ( Fig.   2 and Table 1). These dimers are further connected by centrosymmetric pairs of weak N-H···S interactions into chains extending along [101] (Fig. 2). Finally, there is one N-H···O contact between that NH 2 hydrogen atom which is not involved in N-H···S bonding and the dioxole oxygen O1 (Table 1). If this contact is considered as an interaction the chains are additionally linked into a three-dimensional network (Fig. 2).
In the crystal structure the benzo[1,3]dioxole fragments are oriented nearly perpendicular to [001] and are stacked above each other along this direction by the c-glide plane with a repetition period of c/2 = 3.5645 (7) Å implying π-π stacking.

Experimental
All starting materials are commercially available and were used without further purification. The synthesis was adapted from a procedure reported previously (de Oliveira et al., 2012). The hydrochloric acid catalyzed reaction of 3′,4′-(methylenedioxy)acetophenone (10 mmol) and thiosemicarbazide (10 mmol) in a 3:1 mixture of ethanol and water (100 ml) was refluxed for 6 h. After cooling and filtering crystals suitable for X-ray diffraction were obtained.
Elemental analysis: Calc. 50.62% for C, 4.67% for H, 17.71% for N and 13.51% for S; found 50.72% for C, 4.66% for H, 17.70% for N and 13.47% for S. The melting point was determined by differential scanning calorimetry to 187° C and the enthalpy of fusion amount to 25.9 kJ/mol. After melting the compound decomposes.

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 40% probability level.  Crystal structure of the title compound in a view along the a axis with hydrogen bonds shown as dashed lines. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.29 e Å −3 Δρ min = −0.32 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.047 (8) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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.