| Synthesis and Characterization of a Novel Crowned Schiff Base Ligand Linked to Ionic Liquid and Application of Its Co Complex in the tetrazole synthesis |
| کد مقاله : 1225-ICOC |
| نویسندگان |
|
reza sandaroos *1، ساناز نادری2 1عضو هیات علمی 2Chemistry department, University of Birjand, Birjand, Iran |
| چکیده مقاله |
| In this process, as illustrated in Scheme 1, a novel Schiff base ligand simultaneously functionalized with an ionic liquid and a crown ether moiety was successfully synthesized. The ligand was then reacted with cobalt ions to form a stable metal complex, affording the desired homogeneous catalyst. Subsequently, comprehensive characterization of the synthesized catalyst was carried out using FT-IR spectroscopy, TGA, ICP analysis, CHN elemental analysis, and X-ray diffraction (XRD) in order to confirm its structure, chemical composition, and thermal stability [1]. the preparation of 1-substituted-1-H-tetrazole, the corresponding catalyst shown great catalytic activity.This reaction involves a catalyst that promotes the condensation of sodium azide, triethyl orthoformate, and a variety of heterocyclic/aromatic amines. The present method, as a green protocol, offers several advantages, including a simple operational procedure, excellent product yields, mild reaction conditions, minimal chemical waste, short reaction times, and easy catalyst synthesis. By optimizing various reaction parameters, the optimal conditions for achieving the highest yield were identified as 70 °C in water as the solvent, using 0.003 g of the catalyst. Subsequently, various derivatives were investigated under the optimized conditions. In this reaction, aniline gave a yield of 80%, while o-phenylenediamine showed the highest yield at 90% due to the presence of two reactive amino groups. Derivatives containing mild electron-donating groups, such as 4-methoxyaniline, produced yields similar to aniline (80%). In contrast, introducing a single chlorine atom in the para position, as in 4-chloroaniline, did not affect the yield (80%), whereas placing two chlorine atoms at the 2 and 5 positions significantly reduced the yield to 40%, reflecting strong electron-withdrawing effects and increased steric hindrance. Phenolic amines displayed varied behavior: 4-aminophenol afforded a relatively high yield of 85%, while 2-aminophenol, affected by ortho steric hindrance, yielded only 73%. Notably, 4-nitroaniline, despite bearing a strongly electron-withdrawing NO₂ group, produced an exceptionally high yield of 90%, likely due to enhanced electrophilicity at the iminium intermediate during ring formation. Finally, p-toluidine, which contains a weak electron-donating methyl group, gave a moderate yield of 75%. |
| کلیدواژه ها |
| : Ionic liquid, Crown ether, Cobalt complex, tetrazole synthesis |
| وضعیت: پذیرفته شده |