Experimental

R factor = 0.075; wR factor = 0.162; data-to-parameter ratio = 18.8. In the title compound, C13H15ClN2O, there are two crystal-lographically independent but conformationally similar (E)-molecules in the asymmetric unit [dihedral angles between the phenyl ring and a common planar fragment of the 1,3-diazepane moiety = 47.34 (16) and 48.00 (16)]. The seven-membered ring system adopts a chair conformation in both molecules. In the crystal, N—H O hydrogen bonds lead to chains extending along the b-axis direction. Related literature Heterocyclic ketene aminals are a useful synthon for the synthesis of fused heterocycles, see: Huang & Wang (1994). For their bioactivity and potential applications as pesticides and in medicine, see: Kondo et al. (1990); Jordan et al. (2002). For the synthesis, see: Huang & Liu (1989). For a similar structure, see: Yu et al. (2006)