Mannich Bases of 1,2,4‐Triazolones as Potent Anti‐Tubercular and Antifungal Agents

Abstract

Arylsydnone 1 a-b is ring transformed to 1,3,4-oxadiazole 2 a-b and further converted to 1,2,4-triazolones 3 a-b. Condensation of compound 3 a-b with aromatic aldehydes followed by reduction yielded a secondary amine derivative 5 a-d. Subsequent reaction of compound 5 a-d with formaldehyde and various secondary amines in presence of an acid catalyst afforded mannich bases 6 a-p. Single crystals of the intermediate compounds (Schiff bases) 4 a and 4 b are obtained and confirmed by x-ray crystallographic studies. All the final compounds are tested for anti-tubercular and anti-fungal activity. Almost all compounds have exhibited good pharmacological activity. In anti-tubercular activity, especially compounds 6 d and 6 f have shown excellent activities at the drug concentrations 3.12 μg/ml and 6.25 μg/ml respectively. While in antifungal activity against C. albicans, compounds 6 d and 6 m have exhibited good activities at the drug concentrations 6.25 μg/ml and 12.50 μg/ml where as in the antifungal activity against A. fumigatus, only the compounds 6 b and 6 g have exhibited promising activity at the drug concentration 0.20 μg/ ml.

A structural analysis of 2,5‐diaryl‐4H‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐ones: NMR in the solid state, X‐ray crystallography, and GIPAW calculations

“…Due to its biological properties, many other triazol-3-ones, not necessarily having a 2,5-diaryl pattern, have previously been described; they are Ca 2+ conductance openers activated potassium channels, [2] antimicrobials, [3] antifungals, [4,5] TNF-α inhibitors, [6] selective CB1 receptor antagonists, [7] angiotensin II AT1 receptor antagonists, [8,9] antioxidants, [10] and AChE inhibitors. [11] A thorough understanding of biological properties requires information about the structure of molecules, among them tautomerism [1] and conformational isomerism.…”

Synthesis of Antifungal Heterocycle-Containing Mannich Bases: A Comprehensive Review

“…Remarkably, compound 65a exhibited superior activity compared to the standard fluconazole, and compound 65b displayed com-parable activity. While some derivatives exhibited sensitivity to higher drug concentrations, others demonstrated potential for further development [79].…”

Green Route for the Synthesis of Oxadiazole Derivative Containing Benzimidazole Moiety and Its Mannich Bases: In-Vitro Antimicrobial Activity

“…As Mannich bases have amine groups, they are physiologically active. The most important use for the Mannich bases is in pharmaceutical industries as they possess antibacterial [1][2][3][4] , antifungal [5][6] , anticancer [7][8][9][10] , antioxidant [11][12] , antimalarial 13 , antiinflammatory [14][15] , anti-proliferative 16 and anti-diabetic 17 properties. Moreover, Mannich bases are important pharmacophores in treating thrombosis caused by antioxidants.…”