rac-Ethyl (2Z)-3-{2-[(Z)-4-eth-oxy-4-oxobut-2-en-2-yl-amino]-cyclo-hexyl-amino}-but-2-enoate

The asymmetric unit of the title compound, C(18)H(30)N(2)O(4), contains two independent mol-ecules. In each mol-ecule, the cyclo-hexane ring adopts a chair conformation with equatorial orientation of the substituents, and the conformation is stabilized by two intra-molecular N-H⋯O hydrogen bonds, forming rings of S(6) graph-set motif. One eth-oxy group and one ethyl group are disordered over two sets of sites with refined occupancy ratios of 0.704 (2):0.296 (2) and 0.505 (3):0.495 (3), respectively. In the crystal, a weak inter-molecular C-H⋯O hydrogen inter-action is observed, involving the O atom of the major component of the disordered eth-oxy group.