Crystal structure of p-[N-methyl(diethoxyphosphonyl)-(4-dimethylaminophenyl)]toluidine - a potential cytotoxic agent

The structure of an alpha-aminophosphonic acid diester, p-[N-methyl(diethoxyphosphonyl)-(4-dimethylaminophenyl)]toluidine, was determined by single-crystal X-ray diffraction. The compound is a racemic mixture and crystallizes as colourless prisms in a centrosymmetric manner in the monoclinic crystal system, space group P2(1)/c, with two molecules in the asymmetric unit. One of the ethyl groups in one of the non-equivalent molecules exhibits a disorder. The bond lengths and angles, as well as the conformations of the two molecules, are comparable. Two intermolecular hydrogen bonds of the type N-H center dot center dot center dot O connect the non-equivalent molecules into dimers, and stabilize the crystal structure.