Synthesis and Structure of Indole-, Pyridine-, and Benzimidazole-Containing Nitroethenes

Previously unknown 2-(1,2-dimethylindol-3-yl)-1-nitroethene was synthesized, and procedures for preparing 2-(1-methylbenzimidazol-2-yl)- and 2-(3-pyridyl)-1-nitroethens were improved. The structures of the products were determined by spectroscopic methods and from their dipole moments. According to single crystal X-ray diffraction data, the ( E )-2-(1-methylbenzimidazol-2-yl)-1-nitroethene molecules are virtually planar and are packed in stacks in the crystal lattice, with appreciable stacking interaction.