Microwave assisted regioselective synthesis of quinoline appended triazoles as potent anti-tubercular and antifungal agents via copper (I) catalyzed cycloaddition.

Quinolin-3-yl-methyl-1,2,3-triazolyl-1,2,4-triazol-3(4H)-ones 8j-v were synthesized by click chemistry as an ultimate tactic where [3 + 2] cycloaddition of azides with terminal alkynes has been evolved. Herein, we are inclined to divulge the implication and prevalence of CuSO4·5H2O and THF/water promoted [3 + 2] cycloaddition reactions. The foremost supremacy of this method are transitory reaction times, facile workup, excellent yields (88-92%) with exorbitant purity and regioselective single product formation both under conventional and microwave method. Docking studies illustrated strong binding interactions with enzyme InhA-D148G (PDB ID: 4DQU) by means of high C-score values. The anti-tubercular and antifungal screening of synthesized compounds proclaimed promising activity. The in vitro and in silico studies imply that these triazoles appended quinolines may acquire the ideal structural prerequisites for auxiliary expansion of novel therapeutic agents.

Serendipitous Formation of 2H-Pyrazolo[3,4-d]pyridazin-7(6H)-ones from 3-Arylsydnones.

Fused nitrogen heterocyclesnamely, pyrazolo[3,4-d]pyridazin-7(6H)-ones have been obtained by exploiting the 1,3-dipolar nature of N-arylsydnones, from hydrazones of 3-aryl-4-acetylsydnones via the Vilsmeier-Haack strategy. Facile intramolecular nucleophilic addition followed by CO2 elimination under reflux or upon microwave irradiation was presented. Plausible mechanisms for the formation of the title compounds are proffered. Structure confirmatory evidence came from single-crystal X-ray crystallography.

Click chemistry based regioselective one-pot synthesis of coumarin-3-yl-methyl-1,2,3-triazolyl-1,2,4-triazol-3(4H)-ones as newer potent antitubercular agents.

Coumarin-3-yl-methyl-1,2,3-triazolyl-1,2,4-triazol-3(4H)-ones (8k-z) were synthesized via copper(I)-catalyzed azide-alkyne cycloaddition click chemistry. The synthesized hybrid molecules were characterized by spectral studies. Compounds 8k-z were screened for their in vitro anti-TB activity by using the Microplate Alamar Blue assay and for cytotoxicity using the MTT assay. Some of the compounds were found to be most potent against the tested Mycobacterium tuberculosis H37Rv strain with a MIC of 1.60 µg/ml. Further, docking the compounds into the InhA binding pocket showed strong binding interactions and effective overall docking scores were recorded. The drug-likeness and toxicity studies were computed using Molinspiration and Protox, respectively.

Synthesis, Photophysical and Computational Study of Novel Coumarin-based Organic Dyes.

A series of novel coumarin pyrazoline moieties combined with tetrazoles, 3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one, 6-chloro-3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one, 6-bromo-3-(1-phenyl-4-(1H-tetrazol-5-yl)-1H-pyrazol-3-yl)-2H-chromen-2-one and 6-bromo-3-(1-(4-bromophenyl)-4-(1H-tetrazol-5-yl)-1H pyrazol-3-yl)-2H-chromen-2-one7(a-d), were designed and synthesized. Single crystal X-ray diffraction and their interactions were studied by Hirshfeld surface analysis. Thermal stabilities and electrochemical properties of these compounds were examined from differential scanning calorimetry (DSC), thermogravimetric (TGA) and cyclic voltammetric (CV) studies. Their spectroscopic properties were analyzed in various alcohols and general solvents by UV-Vis absorption, fluorescence and time-resolved spectroscopy. In addition, the ground and excited state electronic properties were investigated using density functional theory (DFT). The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and energy band gap (Eg ) values have revealed the effect of substitution of halogens. The substitution has equally affected the ground and excited states of 7(a-d) compounds. The solvatochromism on absorption, fluorescence spectra and fluorescence lifetimes of these compounds was investigated. All these results showed the chromen-2-one of pyrazoline tetrazole derivatives could play an important role in photonic and electronic devices.

Tetrazolylmethyl quinolines: Design, docking studies, synthesis, anticancer and antifungal analyses.

A new series of 2,5 and 1,5-regioisomers of the tetrazolyl group viz., 3-[(5-benzyl/benzylthio-2H-tetrazol-2-yl) methyl]-2-chloro-6-substituted quinoline 6h-q and 3-[(5-benzyl/benzylthio-1H-tetrazol-1-yl) methyl]-2-chloro-6-substituted quinolines 7h-q were synthesized. Docking studies of all these compounds with DNA as target using PDB: 1AU5 and 453D revealed that the compounds 6h and 6i act as covalent cross linker on the DNA helix of the former and intercalate the latter both with higher C score values. Another set of docking studies in the active pocket of dihydrofolate reductase and N-myristoyl transferase as targets to assess antifungal activity revealed that compounds 6k, 6l, 6p and 7q (with bromo and fluro substituents) showcases different binding modes and hydrogen bonding. Further, the compounds were screened for anticancer activity (primary cytotoxicity) against NCI-60 Human tumor cell line at a single high dose (10-5 M) concentration assay. Among the tested compounds, 6h has shown 99.28% of GI against Melanoma (SK-MEL-5) and compound 6i has shown 97.56% of GI against Breast Cancer (T-47D). Further, in vitro antifungal assay against A. fumigatus and C. albicans for these compounds 6h-q and 7h-q revealed potential to moderate activities as compared to the standard.