(2Z, 2'Z)-Diethyl 3,3'-[butane-1,4-diylbis(azanediyl)]bis(but-2-enoate)

The whole molecule of the title beta-enaminoester, C16H28N2O4, is generated by a crystallographic inversion center, situated at the mid-point of the central C-C bond of the 1,4-diamino-butane segment. There are two intramolecular N-H center dot center dot center dot O hydrogen bonds that generate S(6) ring motifs. This leads to the Z conformation about the CC bonds [1.3756 (17) angstrom]. The molecule is S-shaped with the planar central 1,4-diaminobutane segment [maximum deviation for non H-atoms = 0.0058 (13) angstrom] being inclined to the ethyl butylenonate fragment [C-C-O-C-C=C-C; maximum deviation = 0.0710 (12) angstrom] by 15.56 (10)degrees. In the crystal, molecules are linked via C-H center dot center dot center dot O interactions, leading to the formation of an undulating two-dimensional network lying parallel to the bc plane.