Synthesis by deamination reaction and crystal structure at 120 K of (16Z,19E)-18-oxo-N-(pyridin-2-yl)-6,7,9,10-tetra­hydro-18H-dibenzo[h,o][1,4,7]trioxa­cyclo­hexa­decine-17-carboxamide

The new title aza-crown ether has been synthesized by a deamination reaction and its crystal structure has been determined at 120 K. The title mol­ecule contains a 16-membered macrocycle with the conformation of the C—O—C—C—O—C—C—O—C polyether chain being t–g (-)–t–t–g (+)–t (t = trans, 180°; g = gauche, ±60°).
The title compound, C27H24N2O5, is a product of the deamination reaction from aza-14-crown-4 ether containing the γ-piperidone subunit. The title mol­ecule contains a 16-membered macrocycle with the conformation of the C—O—C—C—O—C—C—O—C polyether chain being t–g (-)–t–t–g (+)–t (t = trans, 180°; g = gauche, ±60°). The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 31.11 (14)°. The cavity size inside the macrocycle is 4.72 Å. The macrocycle is significantly flattened as a result of the extended conjugated system. Steric repulsion between the pyridyl­carboxamide fragment and the benzene ring results in a slight deviation of macrocycle from planarity. The structure also features intra­molecular hydrogen bonding, which results in a deviation of the angle between the planes of amide and pyridyl groups from planarity: this angle is 16.32 (18)°. In the crystal, the mol­ecules are linked into infinite zigzag chains via inter­molecular C—H⋯π contacts. The chains are bound into layers parallel to (100) by weak inter­molecular C—H⋯O hydrogen bonds.