3-[5-(4-Bromophenyl)-1H-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 center dot C9H5BrClN, was crystallized from the reaction between 5,5-dimethyl-cyclo-hexane-1,3-dione, triethyl orthoformate and 5-amino-3-(4-bromo-phenyl)pyrazole, which had itself been prepared from the reaction between (Z)-3-(4-bromo-phenyl)-3-chloro-acrylo-nitrile and hydrazine. The compound is a stoichiometric 2:1 cocrystal of the reaction product 3-[5-(4-bromo-phenyl)-1H-pyrazol-3-ylamino]-5,5-dimethyl-cyclo-hex-2-en-1-one and the early reactant (Z)-3-(4-bromo-phenyl)-3-chloro-acrylonitrile. The two independent molecules of cyclo-hex-2-en-1-one are linked by N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds into complex bilayers and the molecules of acrylonitrile are trapped within large cavities in the substructure formed by the cyclo-hex-2-en-1-one molecules.