Application of NMI-TfCl-mediated amide bond formation in the synthesis of biologically relevant oxadiazole derivatives employing less basic (hetero)aryl amines

NMI-SO2Cl2-Mediated Amide Bond Formation: Facile Synthesis of Some Dihydrotriazolopyrimidine Amide Derivatives as Potential Anti-Inflammatory and Anti-Tubercular Agents

Facile access to some novel biologically relevant dihydrotriazolopyrimidine carboxylic acid-derived amide analogues using NMI/SO2Cl2, and aromatic and aliphatic primary and secondary amines, is reported herein. The role of N-methylimidazole (NMI) as the base and sulfuryl chloride (SO2Cl2) as the coupling reagent has been effectively realized in accessing these molecules in good to excellent yields. The feasibility of the developed protocol has also been extended to the gram-scale synthesis of N-benzylbenzamide in a 75% yield from benzoic acid and benzyl amine. The newly synthesized compounds were tested via in vitro anti-inflammatory and anti-tubercular activity studies. The compounds 6aa and 6be were found to be the most active anti-inflammatory agents, whereas 6cb and 6ch were found to exhibit promising anti-tubercular potency when compared to other synthesized molecules. The structure-activity relationship (SAR) studies revealed the importance of the presence of electron-donating functionalities in enhancing the anti-inflammatory potential of the newly synthesized molecules. However, the presence of electron-withdrawing substituents was found to be significant for improving their anti-tubercular potency.

Evaluation of Anti-Inflammatory and Anti-Tubercular Activity of 4-Methyl-7-Substituted Coumarin Hybrids and Their Structure Activity Relationships

Four sets of previously synthesized 4-methyl-7-substituted coumarin derivatives were screened for their in vitro anti-inflammatory and anti-tubercular activities. The anti-inflammatory potential of 3a-t, 5a-o, 6a-n, and 7a-f synthesized compounds was evaluated by an anti-denaturation assay using diclofenac sodium as the reference standard. Evaluation of the anti-tuberculous activity of the mentioned compounds was performed by the Resazurin test method against four different TB strains using rifampicin and isoniazid as reference drugs. Based on the anti-inflammatory results, compounds 3o, 5f, 6c, and 7d proved to be the most active compounds in their respective series. Additionally, compounds 3k-n, 5b-d, 6d-f, 6k, 7a, and 7f were found to be the most potent anti-tuberculous agents. In fact, most of the screened compounds exhibited promising activity profiles compared to the respective standard drugs. The structure-activity connections revealed a few intriguing aspects, indicating that the presence of electron-donating and nitrogen-rich fragments boost the anti-inflammatory effects of the examined compounds. However, the presence of electron-withdrawing substituents was required to boost the anti-tubercular activity of the evaluated compounds.

Exploration of NMI-MsCl mediated amide bond formation for the synthesis of novel 3,5-substituted-1,2,4-oxadiazole derivatives: synthesis, evaluation of anti-inflammatory activity and molecular docking studies

We herein report the facile synthesis of a series of 3,5-substituted-1,2,4-oxadiazole derivatives 9a-e and 10a-e in good to excellent yields by employing NMI-MsCl mediated amide bond formation reaction. The anti-inflammatory potential of the newly synthesized compounds were evaluated by anti-denaturation assay using diclofenac sodium as the reference drug. The compounds 9a and 9d demonstrated promising activity profile when compared to the reference standard. The SAR and molecular docking studies were also carried out for obtaining more details about the profound activity profile of the synthesized molecules. The synthesized compounds were docked against two target proteins TGF-β and IL-1 by AutoDock vina and Auto Dock 4.2.

Design, synthesis and molecular docking studies of some 1-(5-(2-fluoro-5-(trifluoromethoxy)phenyl)-1,2,4-oxadiazol-3-yl)piperazine derivatives as potential anti-inflammatory agents

We herein report the facile synthesis of a series of 3,5-substituted-1,2,4-oxadiazole derivatives in good to excellent yields. The anti-inflammatory potential of the newly synthesized compounds was evaluated by anti-denaturation assay using diclofenac sodium as the reference standard. Some of the compounds exhibited profound activity profile when compared to the standard drug. The molecular docking and SAR studies were carried out at the later stage for gaining more insights about the promising activity profile of the synthesized molecules.