(E)-N-Ethyl-2-[(E)-3-(hydroxyimino)butan-2-ylidene]hydrazinecarbothioamide

In the crystal structure of the title compound, C7H14N4OS, molecules are linked through N—H⋯S and O—H⋯N hydrogen bonds and C—H⋯S interactions, forming chains propagating along [21-1].

In the crystal structure of the title compound, C 7 H 14 N 4 OS, molecules are linked through N-HÁ Á ÁS and O-HÁ Á ÁN hydrogen bonds and C-HÁ Á ÁS interactions, forming chains propagating along [211].
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  Thiosemicarbazones and their metal complexes have attracted significant attention because of their wide-ranging biological and pharmacological activities related to specific structures as well as chemical properties (Cowley et al., 2002;Ming, 2003). In this paper we report the crystal structure of the title compound ( Fig. 1).
In the title compound, C 7 H 14 N 4 OS, the butyl chain is the longest carbon-carbon chain with the hydroxylamine group bound to C2 and the N-ethylhydrazinecarbothioamide moiety bound to C3.

Experimental
The ligand was prepared by mixing a solution of 2,3-butanedione monoxime (1.01 g, 1 mmol) in EtOH (20 ml) with a solution of 4-ethyl-3-thiosemicarbzide (1.19 g, 1 mmol) in EtOH (20 ml). On adding a few drops of glacial acetic acid to the mixture, a solution of yellowish-white color was formed. The reaction mixture then was heated under reflux with stirring for 3 hrs. The mixture was filtered and left to cool; a white precipitate was formed, then collected by filtration and washed by cold EtOH. Colorless crystal was grown by slow evaporation of EtOH at room temperature, yield (66%).

Refinement
The H atoms were positioned geometrically and refined using a riding model with O-H = 0.85; U iso (H) = 1.5Ueq(O), N -H = 0.87; U iso (H) = 1.2Ueq(N), C-H = 0.98; U iso (H) = 1.5Ueq(C) for methyl groups and C-H = 0.99; U iso (H) = 1.2Ueq(C) for methylene group. The highest residual electron density peak is located 0.64 Å from C2 and the deepest hole is located 0.16 Å from H4B.

Figure 2
The crystal packing of the title compound viewed down the a axis. Hydrogen bonds are shown as dashed lines.

(E)-N-Ethyl-2-[(E)-3-(hydroxyimino)butan-2-ylidene]hydrazinecarbothioamide
Crystal data 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.