1297611-18-7Relevant articles and documents
5-Formylsalicylic acid and 5-(benzimidazolium-2-yl)salicylate
Lu, Yu-Bing,Yang, Ping,Huang, Wen-Na,Yang, Yan-Na,Wu, Jian-Zhong
, p. o596-o599 (2010)
Both title compounds are derivatives of salicylic acid. 5-Formyl-salicylic acid (systematic name: 5-formyl-2-hy-droxy-benzoic acid), C8H 6O4, possesses three good hydrogen-bond donors and/or acceptors coplanar with their attached benzene ring and abides very well by Etter's hydrogen-bond rules. Inter-molecular O - H...O and some weak C - H...O hydrogen bonds link the molecules into a planar sheet. Reaction of this acid and o-phenylene-diamine in refluxing ethanol produced in high yield the new zwitterionic compound 5-(benzimidazolium-2-yl)salicylate [systematic name: 5-(1H-benzimidazol-3-ium-2-yl)-2-hy-droxy-benzoate], C14H 10N2O3. Each imidazolium N - H group and its adjacent salicyl C - H group chelate one carboxylate O atom via hydrogen bonds, forming seven-membered rings. As a result of steric hindrance, the planes of the molecules within these pairs of hydrogen-bonded molecules are inclined to one another by ～74°. There are also π-π stacking interactions between the parallel planes of the imidazole ring and the benzene ring of the salicyl component of the adjacent molecule on one side and the benzimidazolium component of the molecule on the other side.
