Synthesis and properties of 4-(3-substituted azulen-1-yl)-2,6- diphenylpyridines

Abstract

The syntheses of 4-azulen-1-yl-2,6-diphenylpyridines substituted at the azulene C-3 moiety with electron donating or withdrawing groups, are reported. When electron-donating groups (EDG) are present, the reaction of the corresponding pyranylium perchlorates and ammonium acetate takes place. Because of the difficulties in the generation of pyranylium salts with electron-withdrawing groups (EWG), the corresponding pyridines are obtained by a PdCl2-promoted substitution of halogen in 4-chloro-2,6- diphenylpyranylium salt, with an azulene derivative followed by an in situ replacement of oxygen with nitrogen. The physical and chemical properties of the pyridines obtained are discussed. © ARKAT.