t-3-Ethyl-r-2,c-7-bis-(4-methoxy-phen-yl)-1,4-diazepan-5-one

The title compound, C(21)H(26)N(2)O(3), crystallizes with two independent mol-ecules in the asymmetric unit. In both independent mol-ecules, the diazepine ring adopts a chair conformation. In the crystal, the independent mol-ecules exist as N-H⋯O hydrogen-bonded R(2) (2)(8) dimers which are linked via N-H⋯O hydrogen bonds, forming tetra-mers. The tetra-mers are linked by C-H⋯O hydrogen bonds. In one of the molecules in the asymmetric unit, the terminal C atom of the ethyl group is disordered over two positions with refined occupancies of 0.742 (4) and 0.258 (4).