2-Amino-4-(4-methoxyphenyl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile acetic acid monosolvate

The crystal structure of the title compound contains the host molecule and acetic acid in 1:1 ratio without undergoing salt formation.

The title compound crystallizes in the triclinic space group P1 with one pyrano[3,2-c]chromene molecule and one acetic acid molecule in the asymmetric unit (Fig. 1).Unexpectedly, although crystallized from a solvent of glacial acetic acid, the -NH 2 group present in the pyranochromene framework was not protonated.The dihedral angle between the planes of the C1-C12/O2/O3 fused ring (r.m.s.deviation = 0.079 A ˚) and the pendant C14-C19 ring is 89.00 (6) , and the C atom of the methoxy substituent deviates by 0.132 (2) A ˚from its attached ring.
In the crystal, the pyrano[3,2-c]chromene molecules are linked by N1-H11Á Á ÁN2 i hydrogen bonds (Table 1) to generate centrosymmetric R 2 2 (12) loops and the dimers are linked into [100] chains by N1-H10Á Á ÁO1 ii links to generate [100] columns.The acetic data reports acid molecules maintain their hydrogen-bonded dimeric form (via pairwise O6-H15Á Á ÁO5 iii links) without any directional interactions with the pyrano[3,2-c]chromene columns (Fig. 2).The acetic acid dimers occupy the space between pyranochromene columns (about 7.4 A ˚) and are positioned approximately parallel to the pyranochromene plane of the host molecule; a weak C15-H6Á Á ÁO5 hydrogen bond occurs between host and guest.The significant difference between the lengths of the C21-O5 [1.197 (3) A ˚] and C21-O6 [1.284 (3) A ˚] bonds infers that the acetic acid molecule remains in its protonated state.

Figure 1
Molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.
data reports

Special details
Geometry.All esds (except the esd in the dihedral angle between two l.s.planes) are estimated using the full covariance matrix.The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry.An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s.planes.

Figure 2
Figure 2 Packing arrangement of the title compound.Hydrogen bonds are shown as dotted lines.

Table 2
Experimental details.