title: Unexpected formation of N-(1-(2-aryl-hydrazono)isoindolin-2-yl)benzamides and their conversion into 1,2-(bis-1,3,4-oxadiazol-2-yl)benzenes.
abstract: Reaction between ortho-phthalaldehyde and various aroylhydrazines unexpectedly yields N-(1-(2-aryl-hydrazono)isoindolin-2-yl)benzamides as major products along with the predictable 1,2-bis-aroylhydrazones. NMR investigation of the major reaction products indicate the presence of a mixture of geometrical isomers, in various ratios. Single crystal X-ray diffraction confirms the proposed structure and indicates a Z configuration of the C═N double bond substitutents. Optimization of the condensation reaction conditions enabled quantitative isolation of the cyclic isomer. Oxidation of the isomers with bis(trifluoroacetoxy)iodobenzene (PIFA) leads to rapid formation of new highly fluorescent 1,2-bis(5-aryl-1,3,4-oxadiazol-2-yl)benzenes.
authors: University of Bucharest, Faculty of Chemistry, 90-92 Panduri Street, RO-050663-Bucharest, Romania.
authors: Codruţa C
authors: CC
authors: Paraschivescu
authors: Mihaela
authors: M
authors: Matache
authors: Cristian
authors: C
authors: Dobrotă
authors: Alina
authors: A
authors: Nicolescu
authors: Cătălin
authors: C
authors: Maxim
authors: Călin
authors: C
authors: Deleanu
authors: Ileana C
authors: IC
authors: Fărcăşanu
authors: Niculina D
authors: ND
authors: Hădade
mesh_terms: D001549:Benzamides / Q000138:chemical synthesis* / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006834:Hydrazines / Q000737:chemistry*; D007462:Iodobenzenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010069:Oxadiazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D009764:o-Phthalaldehyde / Q000737:chemistry*
chemical_list: D001549:Benzamides; D006834:Hydrazines; D007462:Iodobenzenes; D010069:Oxadiazoles; C031596:bis(I,I-trifluoroacetoxy)iodobenzene; D009764:o-Phthalaldehyde