(E)-3-Chloro-N′-hydroxybenzene-1-carboximidamide

The title compound, C7H7ClN2O, crystallizes with two independent molecules in the asymmetric unit. The compound adopts an E configuration across the C=N double bond, as the –OH group and the benzene ring are on opposite sides of the double bond while the H atom of the hydroxy group is directed away from the –NH2 group. In the crystal, molecules are linked to one another through O—H⋯N and N—H⋯O hydrogen bonds, forming chains along [010].

The title compound, C 7 H 7 ClN 2 O, crystallizes with two independent molecules in the asymmetric unit. The compound adopts an E configuration across the C N double bond, as the -OH group and the benzene ring are on opposite sides of the double bond while the H atom of the hydroxy group is directed away from the -NH 2 group. In the crystal, molecules are linked to one another through O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds, forming chains along [010].
The title compound, (I), crystallizes with two independent molecules (A & B) in the asymmetric unit (Fig. 1). The compound prefers an E configuration across the C-N double bond, as the OH group and the benzene ring are on opposite sides of the double bond while the hydrogen atom of the hydroxyl group is directed away from the NH 2 group.

Experimental
To a solution of 3-chlorobenzonitrile (1 mmol) in ethanol was added triethyl amine (2.5 mmol) and NH 2 OH.HCl (3.5 mmol). The reaction mixture was stirred at room temperature for 12hrs. (The reaction was monitored by TLC). The solvent was removed and the crude product was purified by column chromatography using hexane and ethyl acetate as the eluent. Single crystals required for X-ray diffraction measurements were obtained from slow evaporation of the solution of the compound in a mixture of ethanol and dichloromethane (1:4).

Refinement
The hydrogen atoms attached to N and O were located in difference maps and refined isotropically. The remaining H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å with isotropic displacement parameters set to 1.2 times of the U eq of the parent atom.

Computing details
Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 and SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008   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.