(E)-3,4,5-Trimethoxy-N′-[(4-oxo-4H-chromen-3-yl)methylidene]benzohydrazide

In the title chromone-tethered benzohydrazide derivative, C20H18N2O6, the atoms of the E-3-(hydrazonomethyl)-4H-chromen-4-one segment are essentially coplanar, the largest deviation being 0.065 (6) Å. The dihedral angle between this segment and the benzene ring of the trimethoxybenzene unit is 40.18 (10) Å. In the crystal, the molecule is linked to its inverse-symmetry equivalent by pairs of N—H⋯O hydrogen bonds and C—H⋯π interactions. The –CH=N—NH– segment is stacked on the benzene ring of the chromone unit of a translation-related equivalent molecule [centroid–centroid distance = 3.413 (6) Å].

In the title chromone-tethered benzohydrazide derivative, C 20 H 18 N 2 O 6 , the atoms of the E-3-(hydrazonomethyl)-4Hchromen-4-one segment are essentially coplanar, the largest deviation being 0.065 (6) Å . The dihedral angle between this segment and the benzene ring of the trimethoxybenzene unit is 40.18 (10) Å . In the crystal, the molecule is linked to its inverse-symmetry equivalent by pairs of N-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions. The -CH N-NHsegment is stacked on the benzene ring of the chromone unit of a translation-related equivalent molecule [centroidcentroid distance = 3.413 (6) Å ].
We acknowledge University of Shizuoka for instrumental support.

Refinement
The C(sp 2 )-and N(sp 2 )-bound hydrogen atoms were placed in geometrical positions [C-H 0.95 Å, U iso (H) = 1.2U eq (C), N-H 0.88 Å, U iso (H) = 1.2U eq (N)], and refined using a riding model. Hydrogen atoms of methyl groups were found in a difference Fourier map, and a rotating group model was applied with distance constraint [C-  The molecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level.
Hydrogen atoms are shown as small spheres of arbitrary radius.

Figure 2
A crystal packing view of the title compound. Intermolecular N-H···O hydrogen bonds are represented by dashed lines.