Conventional and Microwave-Assisted Synthesis, Antitubercular Activity, and Molecular Docking Studies of Pyrazole and Oxadiazole Hybrids

Abstract

Microwave-assisted organic reaction enhancement (MORE) has become more important in synthetic organic chemistry for efficient resource utilization. In this study, we synthesized bioactive compounds using both traditional and microwave methods. Microwave-assisted synthesis takes less time and produces higher yields and quality than conventional approaches. We reported the synthesis of N′-(1-(2-(3-(4chlorophenyl)-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1,3,4-oxadiazol-3(2H)yl)ethylidene) substituted hydrazides (4a−t). We also tested them against two strains: M. tuberculosis H 37 Ra and M. bovis BCG. Against M. tuberculosis H 37 Ra, the compounds 4e, 4h, 4k, 4p, and 4s were the most effective. Compounds 4f, 4g, and 4s showed significant activity against M. bovis BCG. The structures of newly synthesized molecules were determined using spectral methods. Furthermore, molecular docking investigations into the active site of mycobacterial InhA yielded well-clustered solutions for these compounds' binding modalities producing a binding affinity in the range of −10.366 to −8.037. Theoretical results were in good accord with the observed experimental values. The docking score of compound 4e was −10.366, and the Glide energy was −66.459 kcal/mol.

Design, synthesis, antimicrobial evaluation, and in‐silico studies of some 4‐thiazolidinone hybrids bearing coumarin and pyridine moieties

“…A Shimadzu LC-MS 2010 spectrometer was used to analyze mass spectra. In a nitrogen atmosphere, anhydrous processes were carried out in oven-dried glassware [32].…”

Oxadiazole: A highly versatile scaffold in drug discovery

“…Desai et al [ 102 ] prepared novel pyrazole‐oxadiazole hybrids as potential antitubercular agents. Compounds 76 , 77 , and 78 were the most effective against MTB H 37 Ra in the active state with MICs in the range of 0.92–2.56 μg/ml.…”

Synthesis, Characterization, Antitubercular Activity, and Molecular Docking Studies of Pyrazolylpyrazoline-Clubbed Triazole and Tetrazole Hybrids

“…In recent years, there has been endless interest in the exploration of novel pyrazole-clubbed pyrazoline moieties. A variety of modifications have been made to the pyrazole and pyrazoline moiety to boost its pharmacological effect because pyrazole–pyrazoline derivatives are widely studied for broad-spectrum biological activities. − The pyrazoline derivatives are widely used as anticancer, antibacterial, antifungal, antitubercular, antimalarial, anti-inflammatory, etc. The chemistry of triazole- and tetrazole-fused heterocyclic derivatives has gathered a lot of attention in recent years due to their synthetic and biological importance.…”

“…3 . 5-Chloro-4-(1,3-dioxolan-2-yl)-3-methyl-1phenyl-1H-pyrazole(1) was synthesized by the reaction of derivative A with ethylene glycol in the presence of p-toluene sulfonic acid (p-TSA) in toluene under reflux conditions for h i b i t e d .5−6 h using a Dean-Stark condenser.…”