3‐[5‐(4‐Bromophenyl)‐1 H ‐pyrazol‐3‐ylamino]‐5,5‐dimethylcyclohex‐2‐en‐1‐one–( Z )‐3‐(4‐bromophenyl)‐3‐chloroacrylonitrile (2/1): a stoichiometric cocrystal of a reaction product with one of its early precursors

The title compound, 2C 17 H 18 BrN 3 O·C 9 H 5 BrClN, was crystallized from the reaction between 5,5‐dimethylcyclohexane‐1,3‐dione, triethyl orthoformate and 5‐amino‐3‐(4‐bromophenyl)pyrazole, which had itself been prepared from the reaction between ( Z )‐3‐(4‐bromophenyl)‐3‐chloroacrylonitrile and hydrazine. The compound is a stoichiometric 2:1 cocrystal of the reaction product 3‐[5‐(4‐bromophenyl)‐1 H ‐pyrazol‐3‐ylamino]‐5,5‐dimethylcyclohex‐2‐en‐1‐one and the early reactant ( Z )‐3‐(4‐bromophenyl)‐3‐chloroacrylonitrile. The two independent molecules of cyclohex‐2‐en‐1‐one are linked by N—H⋯N and N—H⋯O hydrogen bonds into complex bilayers and the molecules of acrylonitrile are trapped within large cavities in the substructure formed by the cyclohex‐2‐en‐1‐one molecules.