The crystal structures of three disordered 2-substituted benzimidazole esters

• Published in: Acta crystallographica. Section E, Crystallographic communications Crystallographic communications, 2021-05, Vol.77 (Pt 5), p.473-479
• Main Authors: Harish Chinthal, Chayanna, Yathirajan, Hemmige S, Manju, Nagaraja, Kalluraya, Balakrishna, Foro, Sabine, Glidewell, Christopher
• Format: Article
• Language: English
• Subjects: benzimidazoles; crystal structure; disorder; heterocyclic compounds; hydrogen bonding; Research Communications; supramolecular assembly
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989021003364

The crystal structures of three benzimidazole esters containing aryl or heterocyclic substituents at position 2 are reported, and all three exhibit disorder of mol-ecular entities. In ethyl 1-methyl-2-[4-(prop-2-yn-oxy)phen-yl]-1 -benzimidazole-5-carboxyl-ate, C H N O , (I), the prop-2-yn-1-oxyphenyl unit is disordered over two sets of atomic sites having effectively equal occupancies, 0.506 (5) and 0.494 (5). The propyl substituent in ethyl 1-propyl-2-(pyren-1-yl)-1 -benzimidazole-5-carboxyl-ate, C H N O , (II), is disordered over two sets of atomic sites having occupancies 0.601 (8) and 0.399 (8), and the ester unit in ethyl 1-methyl-2-(5-chloro-3-methyl-1-phenyl-1 -pyrazol-4-yl)-1 -benzimidazole-5-carboxyl-ate, C H ClN O (III), is disordered over two sets of atomic sites having occupancies 0.645 (7) and 0.355 (7). In each of the C-H⋯π(arene) hydrogen bonds in (I), the donor and acceptor form parts of different disorder components, so that no continuous aggregation is possible. The mol-ecules of (II) are linked by a single C-H⋯O hydrogen bond into (10) chains, which are linked into sheets by a π-π stacking inter-action, whereas those of (III) are just linked into (13) chains, again by a single C-H⋯O hydrogen bond. Comparisons are made with the structures of some related compounds.