Toxic Reagents Research Articles

Simultaneous Assessment of the Nitrates and Nitrites in the Ground Water Samples using Optical Spectrophotometry and Validating the Appropriate Wavelength of Measurement

Background: Nitrate is a renowned pollutant in water and soil. Nitrate is used mostly as a nitrogen fertilizer. When nitrate seeps into the ground it can get into drinking water. Traces of nitrite and nitrate in drinking water may lead to methemoglobinemia in infants and with long term exposure is a possible cancer risk. Concentration of nitrate above 45 mg/L as nitrate and 10 mg/L as nitrate-nitrogen is unsuitable for domestic use according to BIS (Bureau of Indian Standards). Methods: Nitrates are mainly determined by the spectrometric, colorimetric and ion chromatography methods. Majority of these methods are slow measurement, laborious and require the use of toxic and expensive reagents. In this study, ultraviolet spectrophotometric method is utilized for detection of nitrate optically with no chemical reagents. This method is simple and cost-effective. Nitrate and nitrite concentrations were analysed at various wavelengths (220 to 370 nm) and 240 nm was found to be efficient for detecting both nitrate and nitrite. Result: Various groundwater samples in and around Karunya Campus and nearby residential places, Coimbatore, Tamil Nadu were analysed and compared with one borewell water sample from West Bengal State which was prone to contaminated ground water. The results show that all the ground water samples have nitrate and nitrite concentration within the permissible limit but the sample from West Bengal has higher concentration compared to Coimbatore samples.

A safe and efficient synthesis of N-Boc-β3-amino acid methyl esters from α-amino acids: applications in the formal synthesis of sedum alkaloids.

β3-Amino acids are essential components in the synthesis of biologically active compounds. However, obtaining them in enantiomerically pure forms remains challenging. This study investigates a safe and efficient method for synthesizing enantiopure N-Boc-β3-amino acid methyl esters, incorporating both natural and unnatural side chains. The procedure avoids the use of expensive and toxic reagents, providing a safer alternative to the hazardous Arndt-Eistert homologation and cyanation reactions, which typically begin with enantiopure α-amino acids. The practical value of this transformation was demonstrated in the formal synthesis of sedum alkaloids.

Synthesis of some derivatives of 1,8-dioxo-octa-hydro xanthene and 9-aryl-hexahydro acridine-1,8-dione using metal ion-exchanged NaY zeolite as heterogeneous catalyst.

A method for synthesizing xanthene and acridine derivatives using transition metal catalysts supported by de-alumination zeolite-NaY is described. Some transition metal ion-exchanged NaY zeolite was prepared and evaluated in a reaction toward the synthesis of xanthene and acridine. The most active catalyst in this field is a heterogeneous copper/zeolite catalyst. The synthesis of xanthene with a wide range of aldehydes/dimedone with a molar ratio of 1/2 and acridine synthesis with a molar ratio of dimedone/aromatic/ammonium nitrate of 2/1/1 was carried out in one pot and solvent-free conditions. Sensing in the presence of supported metal catalysts is operationally simple, does not require expensive or toxic reagents, and gives high yields in a short period.

Green chemistry approach to the synthesis of 2-aryl/heteroaryl substituted 2,3-dihydroquinazolin-4(1H)-ones using lemon juice under concentrated solar radiations as a renewable source.

This study explores a novel and eco-friendly synthesis of 22 derivatives of 2-aryl/heteroaryl substituted 2,3-dihydroquinazolin-4(1H)-ones, compounds with significant medicinal potential, using concentrated solar radiation (CSR) and lemon juice as a natural catalyst. Traditional methods for synthesizing these compounds often involve complex, energy-intensive processes and toxic reagents. In contrast, the method presented here utilizes solar energy and a biodegradable, non-toxic catalyst, aligning with the principles of green chemistry. The reaction, involving 2-aminobenzamide and various aromatic and heteroaromatic aldehydes, was optimized by varying temperature, catalyst concentration, and solvent. Through optimization, a combination of 0.3 mL of lemon juice and CSR achieved a 97% product yield in 10 minutes. A wide range of aromatic and heteroaromatic aldehydes were tested, all of which produced excellent yields, confirming the method's broad applicability. The substrate scope was explored with different aldehydes, containing groups/structures like chloro, bromo, nitro, methyl, methoxy, fluoro, hydroxy, imidazole, thiazole, chromone, pyrrole, and 1,4-dioxane, yielding up to 97%. Comparative studies with other catalysts and solvents confirmed the superior efficiency of lemon juice. This study not only demonstrates a sustainable approach to synthesizing 2,3-dihydroquinazolin-4(1H)-ones but also highlights the potential of solar energy in organic synthesis, offering a viable alternative to conventional methods. This environmentally benign method offers an efficient and sustainable route for synthesizing 2,3-dihydroquinazolin-4(1H)-one derivatives.

Metal-free iodination of arylaldehydes for total synthesis of aristogins A-F and hernandial.

Iodine is one of the most effective sources for iodination of aromatic compounds; however, its electrophilicity is insufficient for direct iodination. The selection of appropriate environmentally friendly and cost-effective oxidants in combination with iodine for the iodination of aromatic rings, along with its application in the synthesis of natural products, holds significant importance. A highly efficient method utilizing I(III) as the initiator has been successfully developed for monoiodination of arylaldehydes. The method demonstrates good compatibility with a wide range of (hetero)aromatic aldehydes, resulting in moderate to excellent yields, without the need for any toxic, volatile or explosive reagents. The synthesis of seven natural products, namely aristogins A-F and hernandial, was achieved through this iodination followed by Ullmann-type coupling.

The development of a novel bio-based corrosion inhibitor: using biomass-derived 5-hydroxymethylfurfural (5-HMF) as a starting material.

An environmentally friendly corrosion inhibitor was prepared from the bio-based platform 5-hydroxymethylfurfural. This corrosion inhibitor was confirmed to be an efficient mixed-type corrosion inhibitor through a weight loss experiment and electrochemical experiment. Both thermodynamic and kinetic parameters were calculated and discussed, indicating that the adsorption of this bio-based inhibitor on a steel surface is a chemisorption process. Moreover, quantum chemical calculations were performed and further confirmed the formation of an effective productive film of this bio-based inhibitor on the metal surface. It is worth noting that the synthesis route of this bio-based corrosion inhibitor is green and environmentally friendly, and does not involve toxic chemical reagents.

Recovery of valuable metals from spent lithium-ion batteries through an ecofriendly catalytic approach

The rapid growth of lithium-ion batteries (LIBs) used in electric vehicles is amplifying the importance of recycling valuable materials from spent batteries. Current recycling technologies utilize extractive metallurgical processes to recover metals, particularly from cathode materials. However, pyrometallurgy requires high temperatures for smelting, while hydrometallurgy relies on toxic chemical reagents for leaching. Here, we present a catalytic strategy designed to overcome the energy and environmental challenges associated with metallurgical processes. The extraction reaction is conducted using an HxRuO2 catalyst in the presence of HNO3, H2, and CO2. Extraction is achieved through the selective hydrogenation of nitrate to ammonia, followed by the carbonation of leached metal species. The catalytic process successfully achieves nearly complete recovery of Co and Li as carbonates from LiCoO2. Furthermore, we demonstrate the versatility of this catalytic approach in recovering metals from various cathode materials, including spent LIBs. This newly developed one-pot method offers a promising industrial process for recycling valuable metals from spent batteries in an atom-efficient and environmentally friendly manner, without generating waste.

Green synthesis of polyimide by using an ethanol solvothermal method for aqueous zinc batteries.

Polyimides (PIs) are welcomed by battery researchers because of their exceptional heat resistance, structural design versatility, and ion-bearing capabilities. However, most of the reported PIs are synthesized by using toxic and hazardous reagents, such as ethylenediamine, p-phenylenediamine, 1-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), etc., which are not conducive to environmentally friendly development. In this paper, we aim at employing green solvents and raw materials to prepare PIs using a facile solvothermal method. The reactants are urea and 1,4,5,8-naphthalene tetracarboxylic acid dianhydride (NTCDA). The solvents include pure water, pure ethanol, or water-ethanol mixed solvent. The volume ratio of ethanol in the mixed solvent is regulated to obtain the optimum synthesis condition. Depending on the proportion of ethanol, the polyimide products are labeled as U-PI-0, U-PI-50, U-PI-100, etc. The polymerization degree and structure of synthesized PIs are characterized by gel permeation chromatography (GPC), X-ray diffraction (XRD), scanning electron microscopy (SEM), etc. The results indicate that U-PIs exhibit diverse morphological features, including small fragmented, strip-like, and sheet-like structures, and have relative molecular weights ranging from 7500 to 83 000. Notably, the sheet-like U-PI-100 possesses the largest specific surface area, reaching up to 4.20 m2 g-1. When employed as an electrode material in aqueous zinc batteries, U-PI-100 demonstrates superior electrochemical performance compared to others. At a charge-discharge rate of 0.05C, the initial charge/discharge capacity of U-PI-100 is measured to be 314.2/443.7 mA h g-1.

Sustainable methods for the carboxymethylation and methylation of ursolic acid with dimethyl carbonate under mild and acidic conditions.

Ursolic acid is a triterpene plant extract that exhibits significant potential as an anti-cancer, anti-tumour, and anti-inflammatory agent. Its direct use in the pharmaceutical industry is hampered by poor uptake of ursolic acid in the human body coupled with rapid metabolism causing a decrease in bioactivity. Modification of ursolic acid can overcome such issues, however, use of toxic reagents, unsustainable synthetic routes and poor reaction metrics have limited its potential. Herein, we demonstrate the first reported carboxymethylation and/or methylation of ursolic acid with dimethyl carbonate (DMC) as a green solvent and sustainable reagent under acidic conditions. The reaction of DMC with ursolic acid, in the presence of PTSA, ZnCl2, or H2SO4-SiO2 yielded the carboxymethylation product 3β-[[methoxy]carbonyl]oxyurs-12-en-28-oic acid, the methylation product 3β-methoxyurs-12-en-28-oic acid and the dehydration product urs-2,12-dien-28-oic acid. PTSA demonstrated high conversion and selectivity towards the previously unreported carboxymethylation of ursolic acid, while the application of formic acid in the system led to formylation of ursolic acid (3β-formylurs-12-en-28-oic acid) in quantitative yields via esterification, with DMC acting solely as a solvent. Meanwhile, the methylation product of ursolic acid, 3β-methoxyurs-12-en-28-oic acid, was successfully synthesised with FeCl3, demonstrating exceptional conversion and selectivity, >99% and 99%, respectively. Confirmed with the use of qualitative and quantitative green metrics, this result represents a significant improvement in conversion, selectivity, safety, and sustainability over previously reported methods of ursolic acid modification. It was demonstrated that these methods could be applied to other triterpenoids, including corosolic acid. The study also explored the potential pharmaceutical applications of ursolic acid, corosolic acid, and their derivatives, particularly in anti-inflammatory, anti-cancer, and anti-tumour treatments, using molecular ADMET and docking methods. The methods developed in this work have led to the synthesis of novel molecules, thus creating opportunities for the future investigation of biological activity and the modification of a wide range of triterpenoids applying acidic DMC systems to deliver novel active pharmaceutical intermediates.

Polydopamine-modified Zn–Al-layered double hydroxide supported silver nanoparticles as recyclable heterogeneous nanocatalyst for reduction of 4-nitrophenol

This article introduces the design and synthesis of Ag NP garlanded polydopamine (PDA)-functionalized Zn–Al-layered double hydroxide (Zn-Al LDH@PDA) as a hybrid green nanocomposite material, hitherto unreported. The precursor Zn-Al LDH@PDA acted as a suitable shelter and stabilizing support for the in situ generated Ag NPs. The electron rich amino functions over the PDA facilitated the toxic reagent free green reduction of Ag ions in situ. A diverse range of advanced methods, including Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDX), elemental mapping, Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HR-TEM), Fast Fourier Transform (FFT), Inductively Coupled Plasma (ICP), N2 adsorption–desorption, and X-ray Diffraction (XRD) were employed to analyze the physicochemical features of the Zn-Al LDH@PDA/Ag nanomaterial. Catalytic performance of the Zn-Al LDH@PDA/Ag nanocomposite was subsequently appraised in the reduction of 4-nitrophenol (4-NP). The reactions were evaluated through time dependent UV–Vis spectroscopic study which proved the excellent potential of the catalyst. The Zn-Al LDH@PDA/Ag NPs nanocatalyst was isolated by centrifuge and stable enough to be reused for 8 consecutive times without considerable loss in activity.

High-strength, anisotropic bamboo hydrogel via in situ lignin modification for ion-selective transport and sensor

Biomass-based anisotropic hydrogels are severely limited in the practical production and applications due to the weak mechanical properties, time-consuming preparation process and toxic chemical reagents. Herein, a high-strength anisotropic bamboo-based hydrogel is fabricated via in situ lignin modification of natural bamboo and flexibility process, with directionally porous structure and superior mechanical properties. The lignin modification with an UV photocatalytic oxidation process maintains the heterostructure of natural bamboo and exposes polar groups, which provide the bonding sites for subsequent flexibility process. Then, the flexible polyacrylamide (PAM) molecular chains are polymerized in the modified bamboo (photonic bamboo) to construct superior-strength anisotropic bamboo/PAM composite hydrogel (BPCH). The synthesized BPCH has an axial tensile strength (123.5 MPa) and a Young's modulus (3.46 GPa) that significantly outdistance all previous biomass-based hydrogels. Benefiting from the unique porous micro-nanostructure, the BPCH serves as an excellent and stable nanofluidic channel for ion-selective transport and presents the ion conductivity of 5.75 × 10-4 S cm−1 at a low content. Additionally, the BPCH presents stable bending sensitivity to monitor both macroscopic and tiny human actions, such as finger bending, etc. This design offers a high-strength biomass templates and green process for next-generation anisotropic hydrogels, realizing the high value utilization of the bamboo in the micro/nanofluidic and sensor fields.

Research on the separation process of positive electrode active material and aluminum foil

Separating the cathode active material and aluminum foil is an important step in the recovery of materials from used lithium-ion batteries. It is difficult to separate aluminum foil and positive active material because of the strong bonding of polyvinylidene fluoride (PVDF). During the conventional stripping technology, using corrosive acids/alkalis, toxic reagents and releasing toxic gases such as dioxins and HF, which are harmful to human health and the environment. In the study, a low-toxic, efficient and low-cost solvent consisting of “propylene glycol and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][BF6]) ionic liquid” was used to solve these questions. The experimental results showed that the separation rate of the positive active material from the aluminum foil was more than 99 % when the anodes were stirred in propylene glycol and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][BF6]) ionic liquid (the volume ratio of 5:1) at 140 ℃ for 30 min. This work would provide an insight into the environmentally friendly, simple and effective solution to separate of cathode material and aluminum foil in waste lithium-ion batteries.

Synthesis and characterization of fullerene modified with copper nanoparticles catalyzed C[sbnd]H bond activation as a sustainable and green catalyst for electro synthesis of benzothiazole derivatives

In this study, our focus was on synthesizing and characterizing a fullerene modified with copper nanoparticles. This modified fullerene catalyzes for the eco-friendly synthesis of benzothiazole 5(a-m) derivatives. These derivatives are obtained through the reaction of 2-iodoaniline 1(a-f), toluene 2(a-e), and Na2S resulting in good yields (89–94 %). The nanocomposite catalyst underwent thorough characterization using various analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET), Thermogravimetric analysis (TGA), Ultraviolet (UV), X-ray photoelectron spectroscopy (XPS), Cyclic voltammetry (CVs) and X Ray Diffraction Analysis (XRD) spectroscopy. By utilizing this catalyst, we achieve a more environmentally friendly approach to synthesis, reducing the requirement for hazardous and toxic reagents, and minimizing waste generation through reusability. The products obtained in this study were characterized using melting point determination, 1HNMR spectroscopy, and CHN analysis. These analytical techniques were employed to establish the identity and purity of the synthesized compounds.

Oxidative C-F Bonds Activation Using Electrochemical Techniques

Fluorinated organic compounds are widely used in diverse areas such as pharmaceuticals, agrochemicals, and materials science, and occupy an important position in modern chemistry.[1] Consequently, there has been a large library of fluorine-containing chemicals. Thus, the evolution of defluorination reactions using abundant fluorinated organic compounds as starting materials is expected to lead to further development in various fields. For example, it is expected to be applied to the synthesis of medical and agrochemical products with new functions using defluorination reactions, as well as to the defluorination process of polyfluorinated organic compounds that are highly persistent in the environment.The inherent challenge of C-F functionalization is the highly stable and strong nature of C-F bond. To tackle this problem, various methods have been proposed to activate C-F bonds using transition metal complexes, and Lewis acids. However, these methods have some issues that using expensive heavy metals and toxic reagents. Recent years have seen a focus on the development of economical and environmentally friendly defluorination reactions, especially C-F bonds activation based on efficient energy input using electrochemical or photochemical methods. As for photochemical methods, Gouverneur and co-workers developed photocatalytic methods for the selective hydrodefluorination and defluoroalkylation of trifluoromethyl(hetero)arenes using 2,4,5,6-tetrakis(diphenylamino)isophthalonitrile as an organophotocatalyst.[2] As for electrochemical methods, Cheng and co-workers reported a defluorinative method to convert α,α,α-trifluoromethyl cinnamates to gem-difluorostyrenes using electrochemical reduction.[3] These methods of defluorination still have limitations in terms of the versatility of the substrates where only substrates with π-system or have electron acceptors like carbonyl groups are suitable for cleaving C-F bonds presumably for the facile single electron reduction. Thus, the activation and functionalization of C-F bonds in the aliphatic backbone by electrochemical or photochemical means still remain a challenge.In this work, we have developed an electrochemical C-F bond activation and functionalization under oxidative conditions. After exploring the reaction conditions, the electrochemical defluorination reaction of 1-fluoroadamantane was found to proceed in weakly coordinating electrolyte composed of 0.1 M Bu4NB(C6F5)4/CH2Cl2. Nucleophiles such as allyltrimethylsilane and 4,4,5,5-tetramethyl-2-(p-tolyl)-1,3,2-dioxaborolane were applicable to affording 1-allyladamantane (72% yield) and p-(1-adamantyl)toluene (52% yield), respectively. In this reaction, the use of a divided cell was found to be necessary, evidencing that the defluorination reaction proceeds oxidatively at the anode.In conclusion, we have successfully developed the first electrochemical defluorinative functionalization system under oxidative conditions, which potentially become a complementary strategy of electro-reductive counterpart of the defluorinative transformation of organic molecules. In the presentation, an exploration of the substrate scope, electrochemical studies, and the mechanistic proposal of the reaction will also be discussed.[1] Y. Ogawa, E. Tokunaga, O. Kobayashi, K. Hirai, N. Shibata, iScience., 2020, 23, 101467–101467.[2] J. B. I. Sap, N. J. W. Straathof, T. Knauber, C. F. Meyer, M. Médebielle, L. Buglioni, C. Genicot, A. A. Trabanco, T. Noël, C. W. am Ende, V. Gouverneur, J. Am. Chem. Soc., 2020, 142, 20, 9181–9187.[3] J. Sheng, N. Wu, X. Liu, F. Liu, S. Liu, W. Ding, C. Liu and X. Cheng, Chin. J. Org. Chem., 2020, 40, 11, 3873–3880. Figure 1

Simple practical synthesis of 3,3-difluoropyrrolidine from 2,2-dichlorotrifluoro-1-iodoethane

Novel simple approach was elaborated for the preparation of 3,3-difluoropyrrolidine hydrochloride starting from commercially available technical 2,2-dichlorotrifluoro-1-iodoethane. Its radical addition to ethylene afforded the corresponding iodide that was transformed into the primary amine. The last one was heated with sodium hydrosulfide to form previously unknown 3,3-difluoropyrrolidine-2-thione which was converted into the target product in high yield. The whole transformation does not require the use of toxic, flammable, explosive and hazardous reagents as well as column chromatography purification. Alternative syntheses have been proposed for the intermediate and target compounds.

Electrochemical N-Aroylation of Sulfoximines by Using Benzoyl Hydrazines with H2 Generation.

Developed here is a robust electrochemical cross-coupling reaction between aroyl hydrazine and NH-sulfoximine via concomitant cleavage and formation of C(sp2 )-N bonds with the evolution of H2 and N2 as innocuous by-products. This sustainable protocol avoids the use of toxic reagents and occurs at room temperature. The reaction proceeds via the generation of an aroyl and a sulfoximidoyl radical via anodic oxidation under constant current electrolysis (CCE), affording N-aroylated sulfoximine. The strategy is applied to late-stage sulfoximidation of L-menthol, (-)-borneol, D-glucose, vitamin-E derivatives, and marketed drugs such as probenecid, ibuprofen, flurbiprofen, ciprofibrate, and sulindac. In addition, the present methodology is mild, high functional group tolerance with broad substrate scope and scalable.

Synthesis of biphenyl via sustainable Suzuki-Miyaura coupling reaction using mesoporous MCF-supported tin-palladium nanoparticles

The current work presents a novel approach to synthesizing monometallic palladium (Pd) and bimetallic tin-palladium (Sn-Pd) nanoparticles anchored to mesostructured cellular foam silica (MCF). The monometallic catalyst Pd@MCF was prepared by the impregnation method, whereas the bimetallic catalyst Pd@MCF(Sn) was prepared by a green electroless reduction method. Our findings demonstrate that the bimetallic Sn-Pd nanoparticles produced through green electroless reduction exhibit no aggregation or clustering, and possess high and uniform dispersion, smaller average particle size and a narrower distribution of particle size than Pd nanoparticles obtained via impregnation. The synthesis of Pd@MCF(Sn) used tin as one of the metallic components of the catalyst and also as a reducing agent rather than conventionally used harmful reducing agents in the electroless reduction method. Remarkably, the introduction of tin into the catalyst system also displays a synergistic effect in the Suzuki-Miyaura coupling (SMC) reaction. The monometallic Pd@MCF catalyst was outperformed by the bimetallic Pd@MCF(Sn) catalyst in terms of catalytic activity for SMC reaction of phenylboronic acid with iodobenzene to produce biphenyl without using toxic reagents, organic solvents, costly phosphine ligands or protective atmospheres. This study also explored and optimized the factors controlling the reaction rate, offering insightful information to improve the production of biphenyl. The reaction follows a second-order kinetics with an apparent activation energy of 8.2 Kcal/mol by applying the Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanism. Here, we present a promising strategy for formulating a highly effective and eco-friendly catalyst for sustainable production of biphenyl using Suzuki-Miyaura coupling reaction.

Enhancing the Conductivity of PEDOT:PSS Films by the Confinement of Ice Crystals.

Rapid developments in organic electronics demand highly conductive and freestanding (PEDOT:PSS) films. However, the synthesis of highly conductive PEDOT:PSS films requires toxic reagents, such as high-concentration acids and bases. Herein, an eco-friendly and cost-effective strategy is reported for improving the conductivity of PEDOT:PSS films through the confinement of ice crystals. The crystallization of water swelled by the film facilitated the phase separation of PEDOT and PSS, and the excess PSS in the skin layer is effectively removed. Moreover, under the confinement effect, the carrier mobility of the film is enhanced through the formation of a well-crystallized PEDOT molecular morphology. A detailed elucidation of aggregate structure evolution in PEDOT:PSS films during annealing, solvent post-treatment, and subsequent confined crystallization is presented herein. After multiple water crystallization cycles, the conductivity of the PEDOT:PSS film increased by over 85%, achieving a maximum of 2564±142Scm-1. Finally, compared to post-treatment with dimethyl sulfoxide (DMSO), the current strategy can improve the Seebeck coefficient by 5.6% and the power factor by 139%.

SYNTHESIS OF GLYCIVIR DERIVATIVES USING MODIFICATION OF SYNTHESIS PROCEDURE STUDYING THEIR ANTIVIRAL ACTIVITY AGAINST ENV-PSEUDOVIROUSES HIV-1

HIV infection still remains a global health problem around the world. The fight against infection is carried out both through preventive measures and timely testing for the presence of HIV and the use of antiretroviral therapy (ART) when it is detected. Researchers are constantly actively searching for new medicinal agents. In this work, new modified methods for the synthesis of glycivir were tested, including changing the holding time of the reaction mixture, varying the amount of starting reagents, adding catalysts, replacing the solvent, and replacing the condensing agent. Ten variants of glycivir were obtained, for each of which, using the MTT test, a 50% cytotoxic concentration was determined against the TZM-bl cell line and antiviral activity on the model of HIV-1 env-pseudoviruses. Sample 10 had the greatest activity against HIV-1 env-pseudoviruses, the synthesis of which involved the complete replacement of phosphorus and pyridine pentachloride with more accessible and less toxic methyl chloroformate and triethylamine in chloroform. These changes made to the original method for the synthesis of glycivir make it possible to obtain a drug that is most similar in biological activity to glycivir, but at the same time replace highly toxic reagents during the synthesis with less toxic and cheaper ones.

Microwave radiation assisted synthesis of NiFe2O4-CoFe2O4 nanocomposites for photocatalytic and photoelectrochemical water splitting applications

Microwave radiation assisted method is emerged as a promising method due to its environmental friendliness, less time and no need toxic or harsh reagents. Herein, we report the synthesis of a NiFe2O4-CoFe2O4 nanocomposites by microwave radiation assisted method and its characterisation using various methods. X-ray Diffractogram (XRD) studied revealed the spinel cubic structure of the NiFe2O4-CoFe2O4 nanocomposites having an average crystallite size of 34 nm. Tetrahedral (594 cm−1) and octahedral (397 cm−1) sites of NiFe2O4-CoFe2O4 are identified by Fourier Transform Infrared (FTIR) spectroscopy as it is having the typical vibrational frequencies. UV–Visible diffuse reflectance (UV–Vis DRS) spectrum indicated that optical bandgap is less for nanocomposites compared to individual components. Transmission electron microscopy (TEM) images show the spherical nature of the nanocomposites. The photocatalytic degradation study of microwave-assisted NiFe2O4-CoFe2O4 nanocomposites is investigated under visible light irradiation against the Rose Bengal and Methylene blue dyes. The developed nanocomposites exhibited enhanced photoelectrochemical hydrogen due to higher charge separation and faster charge transfer at the interface.