Crystal structure of (E)-N-{2-[2-(3-chlorobenzylidene)hydrazinyl]-2-oxoethyl}-4-methylbenzenesulfonamide monohydrate

The title arylsulfonyl glycinyl hydrazone Schiff base compound crystallizes as a monohydrate. In the crystal, a series of O—H⋯O and N—H⋯O hydrogen bonds leads to the formation of corrugated sheets lying parallel to (100).


Chemical context
Hydrazones are an important class of organic compounds in the Schiff base family. The latter display various biological activities such as antioxidant, anti-inflammatory, anticonvulsant, analgesic, anticancer, antiparasitic, cardioprotective, antidepressant, antitubercular and anti-HIV activities. The hydrazone Schiff bases of aroyl, acyl, and heteroaroyl compounds are more versatile and flexible due to the presence of the C O group, an additional donor site. N-Acylhydrazones containing a glycine residue have been investigated extensively in recent years for their biological and medical activities (Tian et al., 2011). Acylhydrazone derivatives which contain an amino acid moiety and an electrondonating substituent in the sulfonyl phenyl ring have been demonstrated to possess good antiviral activity (Tian et al., 2009).
In view of the biological activities of these Schiff bases, which are related to structural aspects, and as part of our studies on the effects of substituents on the structures of N-(aryl)-amides (Gowda et al., 2000;Rodrigues et al., 2011), N-chloroarylamides (Jyothi & Gowda, 2004) and N-bromoaryl-sulfonamides (Usha & Gowda, 2006), we report herein on the synthesis and crystal structure of the title compound. This acylhydrazone derivative contains an amino acid moiety and an electron-donating substituent in the p-toluenesulfonyl ring.

Figure 3
A view along the c axis of the crystal packing of the title compound. Hydrogen bonds are shown as dashed lines (see Table 1 for details), and C-bound H atoms have been omitted for clarity.
bonds lead to the formation of corrugated sheets lying parallel to (100); see Table 1 and Fig. 3. There are also weak C-HÁ Á ÁO contacts present within the sheets (Table 1).

Synthesis and crystallization
The title compound was synthesized in a number of steps. Firstly p-toluenesulfonyl chloride (0.01 mol) was added to glycine (0.02 mol) dissolved in an aqueous solution of potassium carbonate (0.06 mol, 50 ml). The reaction mixture was stirred at 373 K for 6 h, then left overnight at room temperature, filtered and then treated with dilute hydrochloric acid. The solid N-(4-methylbenzenesulfonyl)glycine (L1) obtained was crystallized from aqueous ethanol. Sulfuric acid (0.5 ml) was added to L1 (0.02 mol) dissolved in ethanol (30 ml) and the mixture was refluxed. The reaction was monitored by TLC at regular intervals. After completion of the reaction, the reaction mixture was concentrated to remove excess ethanol. The product, N-(4-methylbenzenesulfonyl)glycine ethyl ester (L2) obtained was poured into water, neutralized with sodium bicarbonate and recrystallized from acetone.
The pure L2 (0.01 mol) was then added in small portions to a stirred solution of 99% hydrazine hydrate (10 ml) in 30 ml ethanol and the mixture was refluxed for 6 h. After cooling to room temperature, the resulting precipitate was filtered, washed with cold water and dried to obtain N-(4-methylbenzenesulfonyl)glycinyl hydrazide (L3).
A mixture of L3 (0.01 mol) and 3-chlorobenzaldehyde (0.01 mol) in anhydrous methanol (30 ml) and two drops of glacial acetic acid was refluxed for 8 h. After cooling, the precipitate was collected by vacuum filtration, washed with cold methanol and dried. It was recrystallized to constant melting point from methanol (457-458 K). The purity of the title compound was checked and characterized by its IR spectrum. The characteristic absorptions observed are 3253.9, 1680.0, 1597.1, 1334.7 and 1161.2 cm À1 for the stretching bands of N-H, C-O, C-N, S-O asymmetric and S-O symmetric, respectively.
Prism-like colourless single crystals of the title compound were grown from a DMF solution by slow evaporation of the solvent.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The water H atoms were located in a difference Fourier map and refined with the O-H distances restrained to 0.85 (2) Å , and with U iso (H) = 1.5U eq (O). The U eq of atoms O1 and O2 were restrained to approximate isotropic behaviour. The NH H atoms were also located in a difference Fourier map and refined with U iso (H) = 1.2U eq (N). The C-bound H atoms were positioned with idealized geometry and refined using a riding model: C-H = 0.93-0.97 Å with U iso (H) = 1.5U eq (C) for methyl H atoms and 1.2U eq (C) for other H atoms. Acta Cryst. (2015). E71, 602-605 research communications

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.

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