Carbon‐13 NMR spectra of isomeric 2‐arylimidazopyridines

Biosynthesis of MgO nanoparticles using Annona squamosa seeds and its catalytic activity and antibacterial screening

“…In 13 C NMR spectrum, the signal at 157 ppm was attributed to the quaternary carbon atom of benzimidazole moiety while 129 ppm signal indicated C1′ carbon atom of phenyl (carbon atom). Other signals were found to be resonated at the recognition position of the aromatic carbon atoms of phenylbenzimidazole as indicated in the literature [21, 22]. (Fig.…”

Imidazo[4,5-b]pyridine Derivatives As Inhibitors of Aurora Kinases: Lead Optimization Studies toward the Identification of an Orally Bioavailable Preclinical Development Candidate

“…The imidazole NH in 2-arylimidazo-[4.5-b]pyridines is a strong hydrogen donor, and the pK a value of the imidazole NH in 2-phenylimidazo[4.5-b]pyridine was reported as 11.07. 33 The hit-to-lead exploration chemistry also suggested that substitution at the 6-position was sterically limited; however, compound 7 was a considerably more potent inhibitor of Aurora-A compared with the 6-unsubstituted counterpart. 27 We had no clear understanding of the interactions of the (piperazin-1-yl)-N-(thiazol-2-yl)acetamide moiety in 7 with the protein.…”

“…However, the SAR data obtained during the hit-to-lead exploration program and modeling studies suggested that the pyridine N and imidazole NH form hydrogen bonds to Ala213 in the hinge region of Aurora-A with the 2-dimethylaminophenyl substituent pointing to the solvent accessible area. The imidazole NH in 2-arylimidazo[4.5- b ]pyridines is a strong hydrogen donor, and the p K a value of the imidazole NH in 2-phenylimidazo[4.5- b ]pyridine was reported as 11.07 . The hit-to-lead exploration chemistry also suggested that substitution at the 6-position was sterically limited; however, compound 7 was a considerably more potent inhibitor of Aurora-A compared with the 6-unsubstituted counterpart .…”

Condensation products of 1‐aryl‐4‐carboxy‐ 2‐ pyrrolidinones with o‐diaminoarenes, o‐aminophenol, and their structural studies

“…The characteristics of the solution and of the rest of the molecule determine the rate of transitions between the tautomer forms. Obviously, dimethylsulfoxide affects specific solvation of the compounds examined [16]. Although six signals of benzimidazole fragment of benzene moiety in 13 C NMR spectra of compounds 2a, 2b, 2d, 2e, 2g, 2k are broadened, they are well resolved.…”

“…The exploration of the structural features by 13 C NMR spectra of such type of compounds excites some problems [16]. Owing to the versatility of the heterocyclic part, two tautomer forms of the benzimidazole fragment are presumed [12,13].…”