Polymorphs of benzimidazole derivatives

Abstract

While growing 2-ethylbenzimidazole crystals from methanol, polymorph 1с is obtained. In polymorphs 1а-с, 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 Н 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 2а, 2b are presented.