Microwave Irradiation In Synthesis Research Articles

Nanoflower hydroxyapatite's effect on the properties of resin‐based dental composite

AbstractTo investigate the reinforcing effect of nanoflower‐like hydroxyapatite (NFHA) in resin‐based dental composites, we synthesized a novel NFHA using microwave irradiation (MW), hydrothermal treatment (HT), and sonochemical synthesis (SS). Silanized NFHA was then used as the reinforcing filler in dental resin composites. We characterized the structure and morphology of various HA nanostructures using x‐ray diffraction, scanning electron microscope, and TEM. The mechanical performance of dental resin composites reinforced with silanized NFHA was measured using a universal testing machine. Spherical HA, synthesized through chemical precipitation (CP), served as the control group. One‐way analysis of variance was employed for the statistical analysis of the acquired data. The results demonstrate that the nanoflower morphology significantly was improved mechanical and physical properties. After conducting trials, the NFHA synthesized using MW and HT showed a substantial enhancement in mechanical and physical properties compared to the other structures. Therefore, it can be concluded that NFHA can serve as a novel reinforcing HA filler, providing regenerative properties to resin composites with sufficient mechanical strength.

Co-Free Heteroatom-Doped P2-Type Layered Oxide Cathodes: Advancing High Power Sodium-Ion Battery Technology

Sodium-ion battery technology has been blooming as an indigenous solution to stationary storage applications, triggering the cultivation of a cutting-edge alternative to the archaic lithium-ion (Li-ion) batteries due to high abundance, inexpensiveness, sustainability, safety and similar redox chemistry as of Li-ion technology 1. Although Na-ion batteries are propitious however, challenges such as long-term stability, high energy density, high specific capacity have impeded the practical application 2. The stepping stone for a successful Na-ion battery lies in the cathode, thus researchers have focused on development of layered oxide cathode. These are classified into P2, P3, O3 phases, depending on the environment of Na (prismatic or octahedral) and the stacking sequence of the anionic layers 3. P2-type Na0.67Ni0.33Mn0.65O2 (NMNO) cathodes offer high theoretical capacity, environmental friendliness, air-moisture stability, facile synthesis, and direct sodium-ion diffusion. However, there are still some setbacks, such as limited reversible capacity, rapid capacity decay, sluggish Na-ion kinetics, cracking and exfoliation in the crystallites 4. In order to overcome the challenges faced by sodium-ion batteries, researchers have employed several strategies such as inert or active cation substitution, limiting the cut-off voltage, surface modification, preparation of mixed-phase materials, sodium compensation additives, selection of binder, and choice of electrolyte 5. One of the most effective strategies is the doping of electrochemically inactive transition metals in layered transition metal oxide cathodes. However, a better understanding of the parameters that govern the stability of these cathodes are still necessary.By exploring the various factors that impact the stability of layered transition metal oxide cathodes, we propose a novel approach to synthesize a durable P2-type Na0.67Ni0.33Mn0.65Nb0.02O2 (NMNNbO) electrode with robust hexagonal crystallites through a quick, energy-efficient and cost-effective microwave-irradiated synthesis technique. Previous studies have utilized modified Pechini or conventional solid-state routes for inactive transition metal doping, which can be expensive, time-consuming and energy-intensive 6. This leads to an efficient cathode material with higher capacity and improved rate capability, which could be produced on a commercial scale at a lower cost due to the reduced synthesis time. A comprehensive investigation of the cathode material through X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron microscopy (XPS), reveals its superior electrochemical performance, stability, and durability. Through the use of advanced in-situ and ex-situ characterization techniques, the mechanism of Na-ion insertion and extraction, phase transition, and crack formation have been elucidated. Additionally, first-principle calculations using density functional theory (DFT) have been employed to gain a deeper understanding on the role of Nb in the cathode material. Electrochemical characterization was done against Na-metal in a half-cell format utilizing the electrolyte, 1 M NaPF6 in ethylene carbonate and propylene carbonate (1:1). The practicality of the material has also been validated through the evaluation of a full-cell performance against pre-sodiated hard carbon anode. A deeper understanding of the parameters affecting the electrochemical performance, can accelerate the development of high power and durable sodium-ion batteries, making them a more viable option for energy storage applications.

A review study on green synthesis of chitosan derived schiff bases and their applications

Chitosan is a bio-degradable, bio-compatible, non-toxic, and renewable biopolymer. The reactive amino group of chitosan has gained importance because using these amino groups can help achieve the different types of structural modification in chitosan. Chemical modification of chitosan via imine functionalization results in the formation of a chitosan Schiff base. The present review covers the green synthesis of chitosan Schiff bases using non-conventional green methods such as microwave irradiation, green solvent, ultrasound irradiation, and one-pot synthesis. These methods are energy-efficient and greener versions of the conventional condensation methods. Scientists have paid significant attention to the chitosan Schiff base because of its unique properties and versatility. These molecules display various biological applications, including antioxidant, antimicrobial, anticancer, antibacterial, and anti-fungal. In addition to biological applications, chitosan Schiff base also has other applications like corrosion inhibition, catalysis, metal ion adsorption, and as a sensor. Available literature particularly shows the different methods for the synthesis of chitosan Schiff bases and their different applications. This review gives detailed insight regarding sustainable approaches to the synthesis of chitosan derived Schiff bases and their applications in various emerging fields.

Recent Advances in Green Approaches for Synthesis of Oxindole Derivatives

Oxindole derivatives are nitrogen-containing, five-membered heterocyclic molecules found in both natural and synthetic substances with diverse biological functions. Owing to their pharmaceutical and therapeutic characteristics, oxindoles have received remarkable attention, and various oxindole-containing substances can be synthesized using many different approaches. With the discovery of the importance of oxindole derivatives in medicinal chemistry, mainly in drug synthesis, the demand for finding sustainable protocols has increased, as most classical methods have their limitations and flaws. Hence, it is crucial to establish efficient and sustainable techniques that are safe, cost-effective, have low energy consumption, and cause minimal environmental impact. Nowadays, the use of green solvents in organic synthesis has received much attention because they prevent the formation of waste, are environmentally friendly, and have easy work-up procedures. Green solvents such as water, deep eutectic solvents, ionic liquids, and polyethylene glycol can substitute hazardous solvents. Microwave irradiation, visible-light irradiation, electrochemical methods, and multi-component synthesis are all described under green approaches. Most of these approaches allow the reaction to proceed rapidly while releasing minimal waste into the environment. Recent discoveries in green chemistry applications can be considered a turning point in organic synthesis. This review focuses on promising green approaches, used for the synthesis of oxindole derivatives, carried out in recent years with typical examples in two sections: green solvents and green techniques.
 Keywords- Oxindole derivatives, Green solvents, Green techniques, Sustainable chemistry, Solvent-free.

Lower Diffusion-Induced Stress in Nano-Crystallites of P2-Na2/3 Ni1/3 Mn1/2 Ti1/6 O2 Novel Cathode for High Energy Na-ion Batteries.

P2-type Na2/3 Ni1/3 Mn1/2 Ti1/6 O2 (NMTNO) cathode is a preeminent electrode material for Na-ion batteries owing to its open prismatic framework, air-moisture stability, inexpensiveness, appealing capacity, environmental benignity, and Co-free composition. However, the poor cycling stability, sluggish Na-ion kinetics induced in bulk-sized cathode particles, cracking, and exfoliation in the crystallites remain a setback. To outmaneuver these, a designing strategy of a mechanically robust, hexagonal nano-crystallites of P2-type Na2/3 Ni1/3 Mn1/2 Ti1/6 O2 (NMTNOnano ) electrode via quick, energy-efficient, and low-cost microwave-irradiated synthesis is proposed. For the first time, employing a unified experimental and theoretical approach with fracture mechanics analysis, the mechanism behind the enhanced performance, better structural stability, and lower diffusion-induced stress of NMTNOnano compared to micro-sized Na2/3 Ni1/3 Mn1/2 Ti1/6 O2 is unveiled and the electrochemical shock map is predicted. The NMTNOnano cathode provides 94.8% capacity retention after 100 cycles at 0.1 C with prolonged performance for 1000 cycles at 0.5 C. The practical viability of this cathode, tested in a full cell against a hard carbon anode delivered 85.48% capacity retention at 0.14mA cm-2 after 200 cycles. This work bridges the gap in correlating the microstructural and electrochemical properties through experimental, theoretical (DFT), and fracture mechanics analysis, thereby tailoring efficient cathode with lower diffusion-induced stress for high-energy Na-ion batteries.

Synthesis and In-silico Study of Novel 1,3,4-Oxadiazole Derivatives : A Biologically active Scaffolds which induce Anti-tubercular activity by targeting Pteridine Reductase and Dihydrofolate Reductase

Heterocyclic compounds possess diverse biological properties that have led to intense study and research of these compounds. One of these compounds is Oxadiazole which has been found to exhibit various pharmacological activities. 1,3,4-oxadiazole having heterocyclic nucleus is a novel molecule which attract the chemist to search a new therapeutic molecule. Research on 1,3,4-oxadiazole and their synthetic analogues have revealed a variety of pharmacological activities including anti-microbial, anti-tubercular and insecticidal agents. Some of these compounds have also analgesic, anti-inflammatory, anti-cancer, anti-HIV agent, anti-parkinsonian and anti-proliferative agent. It was our interested to make novel derivatives of the titled compounds and evaluate the anti-tubercular activities. 1,3,4-oxadiazole and its derivatives (4a-4e) were obtained. The current study discusses the microwave irradiation synthesis of derivatives with the goal of generating new medications with high specificity for mycobacterium tuberculosis and low harm to the human.

Adsorption of Heavy Metals in Contaminated Water Using Zeolite Derived from Agro-Wastes and Clays: A Review

Due to climate change and anthropogenic activities such as agriculture, mining, and urbanization, water contamination has become a very real modern problem. Modern solutions such as activated carbon, reverse osmosis, and ultrafiltration, among others, have been employed in the decontamination of water. These methods are, however, expensive to set up and maintain and therefore have proved a challenge to implement in developing countries. Zeolite materials exhibit excellent structural properties, such as high ion exchange capacity, porosity, and relative surface area, which make them attractive to water decontamination processes. However, conventional zeolites are expensive, and recent research has focused on utilizing low-cost materials such as agro-wastes and clays as raw materials for the synthesis of zeolites. This review aims to discuss the role of low-cost zeolites in their removal of heavy metals and the feasibility of agro-wastes and natural clays in the synthesis of zeolites. Recent research studies based on the synthesis of zeolites from clays and agro-wastes and their application in heavy metal removal have been reviewed and discussed. Agro-wastes such as rice husk ash and sugarcane bagasse ash and layered silicate clays such as kaolinite and smectites are particularly of interest to zeolite synthesis due to their high silica to alumina ratio. Zeolites synthesized through various methods such as hydrothermal, molten salt, and microwave irradiation synthesis have been discussed with their effect on the adsorption of various heavy metals.

A Comparison between Solution-Based Synthesis Methods of ZrO2 Nanomaterials for Energy Storage Applications

The present study is focused on the synthesis of zirconium dioxide (ZrO2) nanomaterials using the hydrothermal method assisted by microwave irradiation and solution combustion synthesis. Both synthesis techniques resulted in ZrO2 powders with a mixture of tetragonal and monoclinic phases. For microwave synthesis, a further calcination treatment at 800 °C for 15 min was carried out to produce nanopowders with a dominant monoclinic ZrO2 phase, as attested by X-ray diffraction (XRD) and Raman spectroscopy. The thermal behavior of the ZrO2 nanopowder was investigated by in situ XRD measurements. From the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, the presence of near spherical nanoparticles was clear, and TEM confirmed the ZrO2 phases that comprised the calcinated nanopowders, which include a residual tetragonal phase. The optical properties of these ZrO2 nanopowders were assessed through photoluminescence (PL) and PL excitation (PLE) at room temperature (RT), revealing the presence of a broad emission band peaked in the visible spectral region, which suffers a redshift in its peak position, as well as intensity enhancement, after the calcination treatment. The powder resultant from the solution combustion synthesis was composed of plate-like structures with a micrometer size; however, ZrO2 nanoparticles with different shapes were also observed. Thin films were also produced by solution combustion synthesis and deposited on silicon substrates to produce energy storage devices, i.e., ZrO2 capacitors. The capacitors that were prepared from a 0.2 M zirconium nitrate-based precursor solution in 2-methoxyethanol and annealed at 350 °C exhibited an average dielectric constant (κ) of 11 ± 0.5 and low leakage current density of 3.9 ± 1.1 × 10−7 A/cm2 at 1 MV/cm. This study demonstrates the simple and cost-effective aspects of both synthesis routes to produce ZrO2 nanomaterials that can be applied to energy storage devices, such as capacitors.

Microwave Irradiated Synthesis of Pyrimidine Containing, Thiazolidin-4- ones: Antimicrobial, Anti-Tuberculosis, Antimalarial and Anti-Protozoa Evaluation

Aim: This study aims to synthesize thiazolidine-4-one compounds with a pyrimidine nucleus and evaluate against different species of bacteria, fungi, protozoa, and the malaria parasite. Background: Microwave irradiation was the best method for synthesizing the thiazolidin-4-one ring system. It took only 15 minutes for synthesizing thiazolidin-4-one while the conventional method required 12 hours. The rapid reaction was the main concern of this research. Objective: Pyrimidine and Thiazolidin-4-one nucleus have broad-spectrum biological activity and when it is introduced with other hetero atoms containing moiety, many types of biological activities have been found; antimicrobial, anti-tuberculosis, anti-protozoa, antimalarial are the main activities. The activity of these compounds inspired us to do extra research on Thiazolidin-4-one fused pyrimidines with different functional groups. The aim of this study is to synthesize a combination of these two ring systems in less time by using a microwave irradiation method and to evaluate new compounds for different bioactivity. Method: 2-(4-Chlorophenyl)-3-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) thiazolidin- 4-ones (6A-J) were synthesized by microwave irradiation to save energy and time. The structure of all newly synthesized motifs was characterized by spectral analysis (1H NMR, 13C NMR, IR, spectroscopy) and screened for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes, antifungal activity against Candida albicans, Aspergillus niger, Aspergillus clavatus, anti-tuberculosis activity against M. tuberculosis H37RV, antimalarial activity against Plasmodium falciparum and anti-protozoa activity against L. mexicana and T. cruzi. Result: Because of microwave irradiation synthesis, time period is very less for preparing the new compound. Biological response given by compounds 6B, 6C, 6D, 6E, 6G, 6H, and 6J was found excellent. Conclusion: Good yield with purity of the newly synthesized thiazolidine-4-one compounds obtained in less time by using microwave irradiation. The biological response of some of the compounds of this series was found excellent.

Synthesis, biological evaluation,and in silico studies of indole-tethered pyrazoline derivatives as anticancer agents targeting topoisomerase IIα.

We herein report a new series of indole-tethered pyrazoline derivatives as potent anticancer agents. A total of12compounds were designed and synthesized by conventional as well as microwave-irradiated synthesis methods. The latter method results in a significant reduction in the duration of reaction along with improved yields. All synthesized derivatives (7a-7l) were evaluated for their cytotoxic activity against A431, HeLa, and MDAMB-231 cell lines. Compounds 7a and 7b were found most potent in the series and demonstrated an IC50 value of 3.17 and 5.16 µM against the A431 cell line, respectively, compared to the standard drug doxorubicin. Compounds 7a and 7b significantly suppress colony formation, migration, and S phase cell cycle arrest of A431 cells. Furthermore, compound 7a regulated the expression of apoptotic proteins causing the downregulation of procaspase 3/9, antiapoptotic protein Bcl-xL, and upregulation of proapoptotic protein Bax in a dose-dependent manner. Topoisomerase enzyme inhibition assay confirmed that compounds 7a and 7b can significantly inhibit topoisomerase IIα. In vivo oral acute toxicity of compounds 7a and 7b revealed that both compounds are safe compared to doxorubicin; cardiomyopathy studies showed normal architecture of cardiomyocytes and myofibrils. In addition, molecular docking studies revealed the possible interaction of compounds 7a and 7b within the active binding site of the topoisomerase enzyme. The 100 ns molecular dynamicsimulation of compounds 7a and 7b proved that both compounds validate all screening parameters.

Ultrasound and microwave irradiated sustainable synthesis of 5- and 1-substituted tetrazoles in TAIm[I] ionic liquid

Ultrasound and microwave irradiated sustainable synthesis of 5- and 1-substituted tetrazoles in TAIm[I] ionic liquid

Synthesis of Frankincense gum stabilized AgNPs by microwave irradiation and their catalytic, antioxidant, and antibacterial properties

Herein, report the microwave irradiation synthesis of AgNPs using frankincense gum (FR) and their antioxidant, catalytic and antibacterial activities. The developed synthetic route for the synthesis of AgNPs is simple, eco-friendly, and economically viable. UV–visible, FTIR, powder XRD, DLS, and TEM techniques have been used for the characterization of synthesized [email protected] FTIR data demonstrated that the CO and –OH functional groups of frankincense gum were playing an essential role in the reduction and stabilization process of the synthesized [email protected] TEM and powder XRD measurements were confirmed that FR stabilized [email protected] were well dispersed, spherical, and high crystallinity with a size of 7 ± 2 nm. In the presence of NaBH4, the catalytic potential of [email protected] was verified for the reduction of Methyl Orange (MO), Rhodamine-B (Rh–B), and Methyl Red (MR) dyes. AgNPs exhibited significant catalytic efficacy for the degradation of MO, Rh–B, and MR dyes. The AgNPs have shown good antibacterial activity against the Bacillus subtilis, Bacillus series, Escherichia coli, and Pseudomonas aeruginosa. The DPPH radical scavenging mechanism was used to test the antioxidant potential of [email protected] at various concentrations.

Synthesis and Chemistry of Diazo Compounds under Microwave Irradiation: A Review

AbstractDiazo compounds such as α‐diazocarbonyls, diazoalkanes, and diazoarenes are well known compounds in organic chemistry. Their synthetic utility is of paramount importance. They are commonly used as precursors of reactive intermediates like ketenes and carbenoids. Their reactions have been traditionally carried out under thermal or photochemical conditions in inert atmosphere. The synthesis and chemistry of such compounds under microwave irradiation have seen steady growth. The present article critically reviews the application of microwave irradiation in synthesis and chemistry of diazoalkanes and α‐diazocarbonyls. The microwave‐assisted reactions via ketenes and carbenes with alcohols, thiols, phenols, amines, imines, alkenes, alkynes, and three‐membered heterocyclic compounds, etc. are described. These reactions furnish synthetically useful building blocks and also biologically relevant heterocyclic compounds. Most reactions are accelerated by the use of microwave irradiation. There are also some reports revealing that the reactions did not occur by conventional heating but yielded products on irradiation with microwaves. The mechanisms of the reactions where necessary and synthetic and biological relevance of the products are highlighted.

Microwave Irradiated Eco-friendly Synthesis of Pyrimidine Derivatives as Potential Antitubercular Agents

The microwave irradiation method is applied for the efficient synthesis of pyrimidine derivatives. The synthetic protocol involves Knoevenagel condensation followed by Michael addition reaction and cyclization of equimolar quantities of aromatic aldehydes, ethyl cyanoacetate and guanidine in the presence of ethanolic NaOH solution to produce corresponding pyrimidine derivatives. The reaction mixture was allowed to reflux under microwave radiation at power level-2 for 7-12 min. The microwave heating technique offers a cleaner reaction with a shorter reaction time and improved product yield as compared to conventional synthesis. The newly synthesized compounds were characterized by their FT-IR, 1H NMR and LC-MS spectral data. All the synthesized pyrimidine derivatives were evaluated in vitro for their antitubercular activity in vitro by using the luciferase reporter phage (LRP) assay method. The antimycobacterial activity was determined in terms of the percent reduction in the relative light unit (RLU). The test compounds exhibited promising antitubercular activity against Mycobacterium tuberculosis H37Rv and clinical isolates, S, H, R and E resistant M. tuberculosis in comparison with the standard drug (isoniazid).

Microwave irradiated synthesis of Schiff bases of 4-(arylideneamino)-5-alkyl-2,4-dihydro-1,2,4-triazole-3-thione containing 1,2,4-triazole segment.

Novel compounds based on the 1,2,4-triazole skeleton were synthesized. A class of 4-amino-5-alkyl-4H-1,2,4-triazole-3-thione created by reaction of thiocarbohydrazide with long-chain aliphatic carboxylic acids, and then the Schiff bases were obtained in the media of heat and microwave waves, in the presence and the absence of a catalyst. Their chemical structures were assayed by elemental analysis, also device spectroscopic methods.

Conventional and microwave irradiated synthesis, biological activity evaluation of highly substituted indole-triazole hybrids

In the present study, a series of new indole-3-carbaldehyde embedded triazole derivatives have been synthesized. 4-{[(1E)-1H-indol-3-ylmethylidene]amino}-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (2) were converted to the corresponding Mannich bases containing flouroquinolone core via a one-pot, three-component reaction. The synthesis of conazole analogues was carried out starting from triazoles by three steps. Reactions were carried out under conventional and microwave-mediated conditions. Various catalysts and solvents were tested to see how they affected conventional and microwave (MW)-induced reactions. The antibacterial characteristics of all the newly synthesized compounds were tested, and the majority of them showed good to moderate activity. The most significant result of our investigation is the high activity of fluoroquinolone derivative compounds that we synthesized as hybrid molecules.

One Pot Microwave Irradiation Synthesis of Spherical and Nanotube Titanates Incorporated Reduced Graphene for Efficient Hydrogen Production Photo-Electrocatalytically

Nanosphere and titanate nanotube (TNT) amalgamated with different graphene oxide (GO) ratios synthesized by one pot microwave irradiation route have presented excellent potential towards hydrogen production photoelectrochemically under solar irradiation. The hybrid nanospherical array of the 50TNT-50GO photocatalyst showed a current density equal 9.2 mA cm−2 at a bias of 0.20 V vs. RHE exceeding those of the nanotubes 30TNT-70GO (4.0 mA cm−2 at 0.38 V) and 10TNT-90GO (3.7 mA cm−2 at 0.4 V). The former electrode also exhibits small Tafel slope value (40 mV dec−1), decreased particle diameter (7 nm), decreased band gap (2.6 eV) and high rate of charges transfer. The hybrid structure elucidation carried out using TEM-SAED, XRD, N2 adsorption, UV–Vis, FTIR and PL techniques approved the interfacial interaction between TNT and GO(RGO) networks that was responsible for the high quantum yield, delay of charges recombination beside the increase in the pore volume.

Heterocyclic androstane and estrane d-ring modified steroids: Microwave-assisted synthesis, steroid-converting enzyme inhibition, apoptosis induction, and effects on genes encoding estrogen inactivating enzymes

d-ring–fused and d-homo lactone compounds in estratriene and androstane series were synthesized using microwave-assisted reaction conditions. Microwave-irradiated synthesis methods were convenient and effective, and provided high yields with short reaction times. Their inhibition of C17,20-lyase and 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) activities were studied in in vitro enzyme assays. d-ring–fused triazolyl estrone analog 24 showed potent inhibition of NADH-complexed 17β-HSD1, with a binding affinity similar to that of the substrate estrone; its inhibition against NADPH-complexed 17β-HSD1 was markedly weaker. Compound 24 also significantly and selectively reduced proliferation of cancer cell lines of gynecological origin. This estrane triazole changed the cell cycle and induced apoptosis of HeLa, SiHa, and MDA-MB-231 cancer cells, measured by both increased subG1 fraction of cells and activation of caspase-independent signaling pathways. A third mode of anti-estrogenic action of 24 saw increased mRNA expression of the SULT1E1 gene in HeLa cells; in contrast, its 3-benzyloxy analog 23 increased mRNA expression of the HSD17B2 gene, thus showing pronounced pro-drug anti-estrogenic activity. Estradiol-derived d-ring triazole compound 24 thus acts at the enzyme, gene expression and cellular levels to decrease the production of active estrogen hormones, demonstrating its pharmacological potential.

One-Pot Multi Component Microwave Assisted Synthesis of 4H-Pyrano [2, 3-c] Pyrazoles in Methanol and their Antibacterial Study

Upon literature studies, pyrano-pyrazoles were found to exhibit the biological activity as antimicrobial agents. So literature employed conventional stirring and reflux condensing to afford different pyrano-pyrazoles. Recent researches adopted the Microwave method, which is a simple and convenient method for organic synthesis. In this work, we reported the synthesis of different 4H-pyrano [2, 3-c] pyrazoles via two different methods, such as microwave & conventional stirring at room temperature. Ethyl acetoacetate, hydrazine hydrate, malanonitrile, and different substituted carbonyl compounds were made to react in the presence of methanol solvent & potassium ter-butoxide, a base catalyst. The microwave method was adopted for all the reactions and found to be more potent than the conventional method. The prepared compounds were characterized by FT-IR, 1HNMR, and 13CNMR. These compounds were screened for anti-bacterial activity against Staphylococcus aureus and E. coli by well diffusion method and showed the excellent antibacterial property. Our In vitro test for antibacterial study involves excellent MIC (µg/ml) and zone inhibition (mm) measurements of all synthesized compounds. Microwave irradiation synthesis hastens the reaction and is completed very fast. Potassium ter-butoxide, a base catalyst, is proved to be a good catalyst for accelerating the reactions. The yield of all synthesized compounds was good. Different 4H-pyrano [2, 3-c] pyrazoles exhibited good potency against Staphylococcus aureus and E. coli. In the presence of a base catalyst, the reactions are faster than in the absence of a catalyst. The microwave method is a good methodology for the green syntheses. Derivatives of 4H-pyrano [2, 3-c] pyrazoles exhibited excellent MIC (µg/ml) and proved to be as good antibacterial agents.

A facile microwave irradiation synthesis of GO/CNTs hybrids doped with MnO2: structural and magnetic analysis

A facile microwave irradiation synthesis of GO/CNTs hybrids doped with MnO2: structural and magnetic analysis