2-Chlorobenzohydrazide

The asymmetric unit of the the title compound, C7H7ClN2O, contains two molecules in which the chlorophenyl and the formic hydrazide units are almost planar (r.m.s. deviations of 0.0081 and 0.0100 Å, respectively, in one molecule and 0.0069 and 0.0150 Å in the other) and are oriented with respect to each other at dihedral angles of 56.8 (2) and 56.9 (2)°. In the crystal, the molecules are consolidated in the form of polymeric chains extending along [010]. R 3 3(10) ring motifs exist due to N—H⋯O and N—H⋯N hydrogen bonds.

The asymmetric unit of the the title compound, C 7 H 7 ClN 2 O, contains two molecules in which the chlorophenyl and the formic hydrazide units are almost planar (r.m.s. deviations of 0.0081 and 0.0100 Å , respectively, in one molecule and 0.0069 and 0.0150 Å in the other) and are oriented with respect to each other at dihedral angles of 56.8 (2) and 56.9 (2) . In the crystal, the molecules are consolidated in the form of polymeric chains extending along [010]. R 3 3 (10) ring motifs exist due to N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds.
In (I), two molecules are present in the asymmetric unit, which differ slightly from each other geometrically. In one molecule, the chlorophenyl group A (C1-C6/Cl1) and the formic hydrazide moiety B (O1/C7/N1/N2) are planar with r. m. s. deviations of 0.0081Å and 0.0100 Å, respectively. The dihedral angle between A/B is 56.8 (2)°. In second molecule, the chlorophenyl group C (C8-C13/Cl2) and the formic hydrazide moiety D (O2/C14/N3/N4) are also planar with r. m. s. deviation of 0.0069Å and 0.0150 Å, respectively and the dihedral angle between C/D is 56.89 (20)°. Each molecule is connected to symmetry related neighbors through classical intermolecular H-bonding of the N-H···O or N-H···N type (Table 1, Fig. 2) with R 3 3 (10) ring motifs (Bernstein et al., 1995) to generate one-dimensional polymeric chains along the Experimental 2-Chlorobenzoic acid (3.44 g, 22 mmol) was converted to methyl 2-chlorobenzoate by refluxing in methanol (20 ml) in the presence of a catalytic amount of sulfuric acid. This ester was converted into the title compound, 2-chlorobenzoylhydrazide, by refluxing with hydrazine hydrate (80 %, 10 ml) in dry methanol using the literature procedure (Moise et al., 2009). M.p. 379-380K.

Refinement
The coordinates of the H-atoms of the NH 2 groups were refined. The remaining H atoms were positioned geometrically with (N-H = 0.86 and C-H = 0.93 Å) and refined as riding with U iso (H) = xU eq (C, N), where x = 1.2 for all H-atoms.

Figure 2
Partial packing diagram (PLATON; Spek, 2009) which shows that the molecules form polymeric chains extending along the [0 1 0] direction forming R 3 3 (10) ring motifs. Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles 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