Crystal structure of chloro­methyl 2-[2-(2,6-di­chloro­phenyl­amino)­phen­yl]acetate

The previously unknown mol­ecular SCXRD structure and crystal-packing pattern of a diclofenac derivative were assessed in detail including intra- and inter­molecular inter­actions such as hydrogen bonds and halogen bonds. The validity of these inter­actions was further evaluated computationally using QM calculations.

The title compound, C₁₅H₁₅Cl₃NO₂, was synthesized from diclofenac and chloro­methyl chloro­sulfate under phase-transfer conditions, and crystallizes in the monoclinic space group P2₁/c. As a result of steric strain, the two adjacent aromatic six-membered rings cannot be co-planar, while the terminal ring on one side of the mol­ecule and the methyl acetate moiety atoms on the other reside roughly in the same plane. The angle between the planes of the two aromatic rings is rather wide at 64.27 (8)°. The crystal is tightly packed and consolidated by a large number and notable range of inter­molecular contacts, including relatively strong classical hydrogen bonds but also halogen bonds and even short contacts between chlorine atoms and π-bonds. The inter­molecular inter­actions were further analysed using DFT methods, the results of which are discussed in comparison to the experimental X-ray data.