2-(3,4-Dimethylanilino)acetohydrazide

The title compound, C10H15N3O, crystallizes in an infinite two-dimensional polymeric network due to intermolecular N—H⋯O hydrogen bonding. Intramolecular N—H⋯N and intermolecular C—H⋯N interactions are also present. The 3,4-dimethylphenyl unit is disordered over two sites with an occupancy ratio of 0.677 (5):0.323 (5). The dihedral angle between the benzene rings of the disordered components is 2.6 (6)°.

The title compound, C 10 H 15 N 3 O, crystallizes in an infinite twodimensional polymeric network due to intermolecular N-HÁ Á ÁO hydrogen bonding. Intramolecular N-HÁ Á ÁN and intermolecular C-HÁ Á ÁN interactions are also present. The 3,4-dimethylphenyl unit is disordered over two sites with an occupancy ratio of 0.677 (5):0.323 (5). The dihedral angle between the benzene rings of the disordered components is 2.6 (6) .

Comment
The hydrazides and their analogues are known to have different biological activities such as tuberculostatic activity, antifungal and monoamine oxidase inhibitory activity (Waisser et al., 1990;Hall et al., 1993). The title compound (I, Fig. 1) has been prepared as an intermediate for further derivatization with various substituted pyridine aldehydes.
The crystal structure of (II) Phenylglycine hydrazide (Gudasi et al., 2007) and the title compound (I) differ due to substitution of the methyl moieties. In the title compound, the 3,4-dimethylphenyl group is disordered over two possible sites with an occupancy ratio 0.677 (5):0.323 (5). The dihedral angle between the benzene rings A (C1A-C6A) and B (C1B-C6B) of the disordered moiety is 2.6 (6)°. The group C (N1/N2/N3/C10/O1) is almost planar with maximum r.m.s. deviation of 0.0457 Å from its mean square plane, and C9 is at a distance of -0.2594 (26) Å. The dihedral angle between A/C and B/C is 89.46 (10) and 87.80 (23)°, respectively. The title compound is stabilized in the form of an infinite two dimensional polymeric network due to intra as well as inter-molecular N-H···O hydrogen bondings (Table 1, Fig. 2).

Experimental
In a first step ethylchloroacetate (2.3 g, 0.0187 mol), the 3,4-dimethylaniline (2.266 g, 0.0187 mol) and triethylamine (1.89 g, 0.0187 mol) were refluxed in 60 ml of THF. The reaction was monitored by TLC and solvent was removed under reduced pressure. The solid residue obtained was washed with water to get reddish precipitate of ethyl [(3,4dimethylphenyl)amino]acetate.
In a second step ethyl[(3,4-dimethylphenyl)amino]acetate (3.41 g, 0.0164 mol) and about three folds of hydrazine hydrate (2.46 g, 0.0492 mol) were refluxed in 20 ml of ethyl alcohol. On evaporation of solvent at room temperature yellow needles of the title compound (I) were obtained.

Refinement
The coordinates of H-atoms of NH 2 group were refined. H-atoms were positioned geometrically, with N-H = 0.86 Å for NH group, C-H = 0.93, 0.96 and 0.97 Å for aryl, methyl and methylene H, respectively and constrained to ride on their parent atoms, with U iso (H) = xU eq (C, N), where x = 1.5 for methyl and 1.2 for all other H atoms.
The benzene rings of the disordered group were fitted using AFIX 66.

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 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.

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