N′-(Butan-2-ylidene)furan-2-carbohydrazide

The title Schiff base compound, C9H12N2O2, was obtained from a condensation reaction of butan-2-one and furan-2-carbohydrazide. The furan ring and the hydrazide fragment are roughly planar, the largest deviation from the mean plane being 0.069 (2)Å, but the butanylidene group is twisted slightly with respect to this plane by a dihedral angle of 5.2 (3)°. In the crystal, intermolecular N—H⋯O hydrogen bonds link pairs of inversion-related molecules, forming dimers of R 2 2(8) graph-set motif.

The title Schiff base compound, C 9 H 12 N 2 O 2 , was obtained from a condensation reaction of butan-2-one and furan-2carbohydrazide. The furan ring and the hydrazide fragment are roughly planar, the largest deviation from the mean plane being 0.069 (2)Å , but the butanylidene group is twisted slightly with respect to this plane by a dihedral angle of 5.2 (3) . In the crystal, intermolecular N-HÁ Á ÁO hydrogen bonds link pairs of inversion-related molecules, forming dimers of R 2 2 (8) graph-set motif.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2605).

Comment
The chemistry of Schiff base has attracted a great deal of interest in recent years. These compounds play an important role in the development of various proteins and enzymes (Kahwa et al., 1986;Santos et al., 2001). In this paper, we synthesized the title compound and reported its crystal structure of the title compound.
The molecular structure of (I) adopts an E conformation with respect to the C=N double bond (Fig.1). The furan ring and the the C5/N1/N2/C6 group are roughly planar with the largest deviation from the mean plane being 0.069 (2)Å but the butan C6/C7/C8/C9 group is slightly twisted with respect to this plane by a dihedral angle of 5.2 (3)°. Distances and bond angles within the furan and the hydrazide moiety agree with related structures found in the literature (Jing et al., 2007a,b;Yao & Jing, 2007;Bakir & Gyles, 2003;Tai et al., 2007a,b;Zhou et al., 2007;Butcher et al., 2007;Zhao et al., 2007. Intermolecular N-H···O hydrogen bonds link the molecules two by two around inversion centers to form dimers with a R 2 2 (8) graph set motif (Etter et al., 1990;Bernstein et al., 1995) (Table 1, Fig. 2).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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.