The synthesis and biological assessment of [[1,2,4]triazolo[4,3-a]pyridine-3-yl]acetamides with an 1,2,4-oxadiazol cycle in positions 6, 7 and 8

Abstract

Fused heterocyclic 1,2,4-triazoles have provided much attention due to variety of their interesting biological properties. Aim. To develop the method for the synthesis of novel 2-[(1,2,4-oxadiazol-5-yl)-[1,2,4]triazolo[4,3-a]pyridine-3-yl]acetamides and conduct the biological assessment of the compounds synthesized. Results and discussion. A diverse set of acetamides newly synthesized consists of 32 analogs bearing an 1,2,4-oxadiazole cycle in positions 6, 7 and 8. A convenient scheme of the synthesis starts from commercially available 2-chloropyridine-3-, 2-chloropyridine-4-, 2-chloropyridine-5-carboxylic acids with amidoximes to form the corresponding 2-chloro-[3-R 1-1,2,4-oxadiazol-5-yl]pyridines, then follows the reaction of hydrazinolysis with an excess of hydrazine hydrate. The process continues via the ester formation with the pyridine ring closure, then the amide formations of the end products are obtained by hydrolysis into acetic acid. Experimental part. A series of new 2-[6-(1,2,4-oxadiazol-5-yl)-, 2-[7-(1,2,4-oxadiazol-5-yl)-, 2-[8-(1,2,4-oxadiazol-5-yl)-[1,2,4]triazolo[4,3-a]pyridine-3-yl]acetamides were obtained in good yields, and their structures were proven by the method of 1 H NMR spectroscopy. The prognosis and study of their pharmacological activity were also conducted. Conclusions. The synthetic approach of obtaining the representatives of 2-[(1,2,4-oxadiazol-5-yl)-[1,2,4] triazolo[4,3-a]pyridine-3-yl]acetamides previously unknown can be used as an applicable method for the synthesis of diverse functionalized [1,2,4]triazolo[4,3-a]pyridine derivatives.

Synthesis and evaluation of pyridine-3-carboxamide analogs as effective agents against bacterial wilt in tomatoes

“…Bacterial wilt incited by R. solanacearum infection is one of the major factor for diseases in tomato and other solanaceous plants that caused drastic loss of tomato fruit worldwide 2 – 5 . The use of traditional pesticides to treat bacterial wilt in plants do not show positive effects and has been proved not very effective 6 , Therefore, discover new bioactive molecules and pesticides agent still represents a daunting task in pesticide science 7 , 8 . About 450 plant species from 54 botanical families have been reported as hosts of R. solanacearum 9 , 10 .…”