Synthesis of new coumarin based acetohydrazones, their correspounding oxadiazoles and oxadiazolines, and the investigation of their antibacterial activity

Journal of Chemical Reactivity and Synthesis

دوره 13، شماره 1، تیر 2023، صفحه 1-19   

نوع مقاله: Research Article

نویسندگان

Narjes Baharvand¹؛ Enayatollah Mottaghinejad^{* 1}؛ Mohsen Sargordan Fardarani¹؛ Hosseini Doust²

¹Department of Chemistry, Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran

²Department of Microbiology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran

چکیده

Here we provide a report on the synthesis, structural recognition and tautomeric behavior of a new series of coumarin-based hydrazide-hydrazones (4-methylcoumarin-7-yl-oxymethyl arylaldehyde acetohydrazones) and their 1,3,4- oxadiazoline and oxadiazole derivatives. The final products were tested for antibacterial activity on both Gram-negative and Grampositive bacteria. Both types of hydrogen, the hydrazone N-H and methylene protons can take part in tautomeric isomerization equilibrium. The synthesis of 1,3,4-oxadiazoles and oxadiazoline bearing coumarin ring was conducted for inferring the isomerization-tautomerization of their hydrazone precursors According to the NMR investigation, We found that, the amide-iminol tautomerization is more probable than keto-enol one. It was further explained via converting the hydrazones to the corresponding 1,3,4-oxadiazoles and oxadiazolines based on the modified procedures. All the synthesized oxadiazoles and oxadiazolines have antibacterial effect on Gram-negative bacteria with respect to Gram-positive bacteria. The active ingredient of the synthesized derivative 8 has the best effect on both Gram-negative and Gram-positive bacteria.      

کلیدواژه‌ها

4-Methylcoumarin؛ Oxadiazoles؛ Anti-bacterial agents؛ Heterocycles