Experimental and theoretical study on the reaction of N3-phenyl-(pyridin-2-yl)carbohydrazonamide with itaconic anhydride

Two new 1,2,4-triazole-containing alkenoic acid derivatives were obtained from the reaction of N-phenyl-(pyridin-2-yl)carbohydrazonamide with itaconic anhydride, depending on the reaction conditions. The structures of 2-((4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl)methyl)acrylic acid or (E)-2-methyl-3(4-phenyl-5-(pyridine-2-yl)-4H-1,2,4-triazol-3-yl)acrylic acid were confirmed by means of 1D and 2D NMR spectroscopic data as well as by single-crystal X-ray diffraction analysis. The experiential 1H and 13C chemical shifts were compared with those calculated with B3LYP, EDF1, and EDF2 density functional theories. The theoretical study of the observed terminal-to-internal alkene isomerization was performed with density functional (DFT) B3LYP/6-31+G∗ method using SM8 water and DMF solvation models. Antimicrobial activities of the newly prepared alkenoic acid derivatives were verified experimentally by a broth microdilution method.

► New isomeric 1,2,4-triazole-containing alkenoic acids are obtained. ► Mechanisms of base-catalyzed and neutral thermal 1,3-proton shifts are studied theoretically. ► The structures are confirmed by 1D and 2D NMR and single crystal X-ray diffraction analysis. ► Antimicrobial activity of the 1,2,4-triazole-containing alkenoic acids are investigated.