(E)-N′-(3-Hydroxy-4-methoxybenzylidene)-4-methoxybenzohydrazide

The title molecule, a benzohydrazide derivative, C16H16N2O4, is twisted with a dihedral angle of 69.97 (5)° between the two benzene rings. An intramolecular O—H⋯O hydrogen bond generates an S(5) ring motif. In the crystal, molecules are linked by N—H⋯O and weak C—H⋯O hydrogen bonds into a chain along the c axis. C—H⋯π interactions are also present.

Cg1 is the centroid of the C1-C6 ring.   (Loncle et al., 2004), antitubercular (Bedia et al., 2006), antimalarial (Melnyk et al., 2006 and antiproliferative (Raj et al., 2007) activities. We have previously reported some crystal structures of this type of compounds (Fun et al., 2011;Horkaew et al., 2011;Promdet et al., 2011). The title compound (I) was synthesized in order to study the effect of functional groups to their bioactivities comparing to the closely related structures. (I) was screened for antibacterial and antioxidant activities.

D-HÁ
Our results show that (I) exhibits moderate antibacterial activity whereas it is inactive for antioxidant activity. The three dimensional structure of (I) was studied in order to gain more details to explain the effect of structure on its bioactivity.
The molecule of the title benzohydrazide derivative ( In the crystal packing (Fig. 2), the molecules are linked by N-H···O hydrogen bonds and weak C-H···O interactions (Table 1) into chains along the c axis. These chains are arranged in a face-to-face manner. The crystal is stabilized by N-H···O hydrogen bonds, weak C-H···O and C-H···π interactions (Table 1).
The mixture was refluxed for around 3 hr. The solution was then cooled to room temperature. Colorless plate-shaped single crystals of the title compound suitable for X-ray structure determination were recrystallized from methanol by slow evaporation of the solvent at room temperature after several days (m.p. 491-492 K).

Refinement
Amide and hydroxy H atoms were located in difference maps and refined isotropically [N-H = 0.887 (18) Å and O-H = 0.87 (2) Å]. The remaining H atoms were positioned geometrically and allowed to ride on their parent atoms, with C-H = supplementary materials sup-2 0.93 Å for aromatic and CH and 0.96 Å for CH 3 atoms. The U iso values were constrained to be 1.5U eq of the carrier atom for methyl H atoms and 1.2U eq for the remaining H atoms. A rotating group model was used for the methyl groups. Fig. 1. The molecular structure of the title compound, showing 60% probability displacement ellipsoids and the atom-numbering scheme. Hydrogen bond was drawn as a dash line. 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 > 2sigma(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.