One-pot Synthesis of a 3,4,5-triaryltriazole from the subsitituted 1,3,4-oxadiazole: Crystal structures characterization

Two heterocyclic compounds, 2-(p-bromophenyl)-5-(2-pyridyl)-1,3,4-oxadiazole (1) and 3-(p-bromophenyl)- 4-phenyl-5-(2-pyridyl)-1,2,4-triazole (2) were successfully synthesized and characterized by UV-vis, FTIR, ¹H NMR, ESI-MS spectra, elemental analysis, and single crystal X-ray crystallography. The structural analysis indicates that 1 is almost a planar molecule but 2 not. The crystal structure of 1 is stabilized by two kinds of intermolecular π- π interactions and two types of intermolecular C-H · N hydrogen bonds, whereas 2 by three kinds of C-H · π interactions and three types of intermolecular C-H · N hydrogen bonds. Additional, 2 can be prepared directly from 1 in an aniline solution at 190°C in a yield of 70%.