POLYMORPHS OF BENZIMIDAZOLE DERIVATIVES

While growing 2-ethylbenzimidazole crystals from methanol, polymorph 1c is obtained. In polymorphs 1a-c, 2-ethylbenzimidazole molecules have a different arrangement in the packing and the position of the ethyl group relative to the benzimidazole plane. At the same time, the character (sequence) of intermolecular N-H...N bonds is maintained. In polymorph 1b with four independent molecules, there is an intermolecular. bond between homonymous molecules. The study of the crystal structure of another benzimidazole derivative (2-(1-hydroxyethyl) benzimidazole (2)) reveals a new polymorph. The results of the comparative analysis of the crystal structures of two polymorphs 2a, 2b are presented.