Synthesis of Functionalized Thiophene Based Pyrazole Amides via Various Catalytic Approaches: Structural Features through Computational Applications and Nonlinear Optical Properties

Green synthesis of novel spiropyrazoline-indolinones in neutral deep eutectic solvents and DFT studies

Novel spiropyrazoline-indolinones (4a-t) have been synthesized successfully in neutral deep eutectic solvents by reacting 5-Cl/Br-isatin (1a-b) with aromatic ketones (2a-b) and a variety of substituted hydrazines (3a-e) in good to excellent yields. This eco-friendly straightforward synthetic protocol discloses good functional group compatibility. The conventional synthetic approach was compared with the greener route of microwave-assisted synthesis of spiropyrazolines using ethanol. This approach utilized mild reaction conditions which furnished high yields in short reaction time employing one pot two-step multicomponent. All new compounds were structurally confirmed by detailed spectroscopic analysis and density functional theory calculations. This method provides efficient access to spiropyrazole derivatives using biodegradable and green solvent.

Green synthesis of highly functionalized heterocyclic bearing pyrazole moiety for cancer-targeted chemo/radioisotope therapy

New derivatives of heterocyclic bearing pyrazole moiety were synthesized (eight new compounds from 2 to 9) via green synthesis methods (microwave-assisted and grinding techniques). 4,6-Diamino-1,3-diphenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile (2) shows high anti-cancer activity against both HepG2 and HCT-116 with IC50 of 9.2 ± 2.8 and 7.7 ± 1.8 µM, respectively, which referenced to 5-Fu which is showing activity of 7.86 ± 0.5 and 5.35 ± 0.3 against both HepG2 and HCT-116, respectively. The cytotoxic activity against HCT-116 and HepG2 was slightly decreased and slightly increased, respectively, by a different pyrazole moiety (compound 5). Pharmacokinetics of compound 2 was carried out using the radioiodination technique in tumour-bearing Albino mice which shows good uptake at the tumour site. The biodistribution showed high accumulation in tumour tissues with a ratio of 13.7% ID/g organ after one hour in comparison with 2.97% ID/g organ at normal muscle at the same time point. As I-131 has maximum beta and gamma energies of 606.3 and 364.5 keV, respectively, therefore the newly synthesized compound 2 may be used for chemotherapy and TRT.

Microwave assisted one-pot access to pyrazolo quinolinone and tetrahydroisoxazolo quinolinone derivatives via T3P®-DMSO catalysed tandem oxidative-condensation reaction

A new approach for the synthesis of two important annulated pyrazolo quinolinone and tetrahydroisoxazolo quinolinone derivatives from multicomponent reactions was achieved by using T3P®-DMSO-catalysed reactions of stable alcohols, cyclic 1,3-dicarbonyl compounds and amino derivatives of phenyl pyrazoles and isoxazole and has been reported for the first time. This reaction occurred via a tandem oxidative-condensation reaction under microwave irradiation and notable characteristics of this protocol are MCR reactions, shorter reaction time, less waste creation, ease of workup, stable precursors, broad substrate scope and functional group tolerance.

Synthesis, Anti-Bacterial and Molecular Docking Studies of Arylated Butyl 2-Bromoisonicotinate Against Clinical Isolates of ESBL-Producing Escherichia coli ST405 and Methicillin-Resistant Staphylococcus aureus

Introduction

Global public health concerns include the emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase Escherichia coli (ESBL-E. coli). These pathogens cause infections that are difficult to treat, which can have fatal outcomes and require lengthy hospital stays. As a result, we created butyl 2-bromoisonicotinate and tested its antibacterial effectiveness against the ESBL-E. coli ST 405 and MRSA pathogens. Natural product discovery is complemented by synthetic compound synthesis because of the latter's potential for superior characteristics, target specificity, scalability, intellectual advantages, and chemical diversity. Because of this, the potential for discovering new medicinal compounds is increased, and the constraints placed on natural sources are overcome. Natural items are tough to obtain since they are hard to isolate and synthesize. Therefore, modern science is actively searching for small molecules as therapeutic agents by applying sustainable techniques that can be commercialized.

Methods

Two patients' blood samples were taken, and the BACTEC/Alert system was used to process them. On blood and MacConkey agar, the positive samples were subcultured and incubated aerobically at 37 °C. Using the VITEK 2 compact system, the isolates were subjected to isolate identification and MIC. MLST of the ESBL-E. coli was performed by PCR. Additionally, Fischer esterification was used to create butyl 2-bromoisonicotinate in excellent yields. A commercially available palladium catalyst was then used to arylate the compound, resulting in medium to good yields of arylated butyl 2-bromoisonicotinates. Using the agar well diffusion assay and the micro-broth dilution method, we assessed the in-vitro activities of the synthesized molecules (3, 5a-h) against clinically isolated ESBL-E. coli ST405, and MRSA. A molecular operating environment was used to carry out in silico validation of the synthesized compounds' binding to the active site and to evaluate the stability of their molecular interactions with the target E. coli 2Y2T protein.

Results

MRSA and ESBL-producing E. coli were identified as the two clinical isolates. While MRSA was also resistant to beta-lactam drugs and least resistant to vancomycin, ESBL-producing E. coli belonged to ST405 and was resistant to cephalosporins and sensitive to carbapenems. Good yields of the desired compounds were produced by our effective and economical synthesis. By using a micro-broth dilution assay, the Molecules (3, 5a, and 5d) were most effective against both resistant strains. The Molecules (3, 5a, 5b, and 5d) also displayed good binding energies.

Conclusion

The butyl 2-bromoisonicotinate displayed antibacterial efficacy against ESBL-producing E. coli ST405 and MRSA strains. After the in-vivo trial, this substance might offer an alternative therapeutic option.

Synthesis of Functionalized N-(4-Bromophenyl)furan-2-carboxamides via Suzuki-Miyaura Cross-Coupling: Anti-Bacterial Activities against Clinically Isolated Drug Resistant A. baumannii, K. pneumoniae, E. cloacae and MRSA and Its Validation via a Computational Approach

N-(4-bromophenyl)furan-2-carboxamide (3) was synthesized by the reaction furan-2-carbonyl chloride (1) and 4-bromoaniline (2) in the presence of Et₃N in excellent yields of 94%. The carboxamide (3) was arylated by employing triphenylphosphine palladium as a catalyst and K₃PO₄ as a base to afford N-(4-bromophenyl)furan-2-carboxamide analogues (5a-i) in moderate to good yields (43–83%). Furthermore, we investigated the in vitro anti-bacterial activities of the respective compounds against clinically isolated drug-resistant bacteria A. baumannii, K. pneumoniae, E. cloacae and S. aureus. The molecule (3) was found to be the most effective activity against these bacteria, particularly NDM-positive bacteria A. baumannii as compared to various commercially available drugs. Docking studies and MD simulations further validated it, expressing the active site and molecular interaction stability.

Facile Synthesis of Functionalized Phenoxy Quinolines: Antibacterial Activities against ESBL Producing Escherichia coli and MRSA, Docking Studies, and Structural Features Determination through Computational Approach

The synthesis of new 6-Bromoquinolin-4-ol derivatives (3a–3h) by Chan–Lam coupling utilizing different types of solvents (protic, aprotic, and mixed solvents) and bases was studied in the present manuscript. Furthermore, their potential against ESBL producing Escherichia coli (ESBL E. coli) and methicillin-resistant Staphylococcusaureus (MRSA) were investigated. Commercially available 6-bromoquinolin-4-ol (3a) was reacted with different types of aryl boronic acids along with Cu(OAc)₂ via Chan–Lam coupling methodology utilizing the protic and aprotic and mixed solvents. The molecules (3a–3h) exhibited very good yields with methanol, moderate yields with DMF, and low yields with ethanol solvents, while the mixed solvent CH₃OH/H₂O (8:1) gave more excellent results as compared to the other solvents. The in vitro antiseptic values against ESBL E. coli and MRSA were calculated at five different deliberations (10, 20, 30, 40, 50 mg/well) by agar well diffusion method. The molecule 3e depicted highest antibacterial activity while compounds 3b and 3d showed low antibacterial activity. Additionally, MIC and MBC standards were calculated against the established bacteria by broth dilution method. Furthermore, a molecular docking investigation of the derivatives (3a–3h) were performed. Compound (3e) was highly active and depicted the least binding energy of −5.4. Moreover, to investigate the essential structural and physical properties, the density functional theory (DFT) findings of the synthesized molecules were accomplished by using the basic set PBE0-D3BJ/def2-TZVP/SMD water level of the theory. The synthesized compounds showed an energy gap from 4.93 to 5.07 eV.

Synthesis and Structure Determination of 2-Cyano-3-(1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl)acrylamide

2-Cyano-3-(1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl)acrylamide (3) was synthesized in 90% yield from condensation of equimolar equivalents of 1-phenyl-3-(thiophen-2-yl)-1H-pyrazole-4-carbaldehyde (1) and 2-cyanoacetamide (2) in boiling ethanol under basic condition for 45 min. The structure of 3 was determined using NMR spectroscopy and single crystal X-ray diffraction.

1H-Pyrazolo[3,4-b]quinolines: Synthesis and Properties over 100 Years of Research

This paper summarises a little over 100 years of research on the synthesis and the photophysical and biological properties of 1H-pyrazolo[3,4-b]quinolines that was published in the years 1911–2021. The main methods of synthesis are described, which include Friedländer condensation, synthesis from anthranilic acid derivatives, multicomponent synthesis and others. The use of this class of compounds as potential fluorescent sensors and biologically active compounds is shown. This review intends to summarize the abovementioned aspects of 1H-pyrazolo[3,4-b]quinoline chemistry. Some of the results that are presented in this publication come from the laboratories of the authors of this review.