Research on Chemical Intermediates最新文献

An intriguing trend in the synthesis of heterocyclic compounds is green chemistry, which involves using environmentally friendly reagents and efficient reactions to suit the demands of the pharmaceutical sector. This study is a part of continuous endeavour to advance novel synthetic approaches for the synthesis of heterocyclic molecules. With lanthanum nitrate hexahydrate as a catalyst, a procedure for the synthesis of tetrazoles was described in this work. The ideal 10% mole ratio of La(NO₃)₃·6H₂O catalyst with DMF solvent produced good yields of the intended products, ranging from 85 to 98%, according to the results. High product yields, cost effectiveness, and operational simplicity are just a few benefits of using La(NO₃)₃·6H₂O as a catalyst in this condensation reaction. The chemical structures of the synthesized tetrazoles were analyzed and characterized using ¹HNMR, ¹³C-NMR, and mass spectra (HRMS).

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In this study, a novel MoO₃-WS₂-g-C₃N₄ (MWg) nanocomposite photocatalyst is synthesized via a combination of heat treatment and hydrothermal method. The synthesis involved the preparation of WS₂-g-C₃N₄ binary heterojunction followed by incorporation of MoO₃ through hydrothermal treatment, resulting in the formation of a hybrid nanocomposite photocatalyst with enhanced activity under visible light irradiation. The different characterization techniques including X-ray powder diffraction through Rietveld refinement, transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), and UV–vis absorption spectra are employed to assess the crystallographic information, morphological growth, chemical compositions and optical bandgaps of the samples. The MWg photocatalyst exhibits improved performance in the degradation of rhodamine B (RhB) dye compared to methylene blue (MB ~ 26%) and methylene orange (MO ~ 31%), achieving ~ 95% degradation within 45 min. The stability and reusability of the MWg sample are confirmed through X-ray diffraction (XRD) pattern analysis before and after photocatalytic reactions, demonstrating its efficacy over multiple cycles. The MWg photocatalyst shows a promising potential for wastewater treatment under visible light irradiation, making it a valuable candidate for environmental remediation applications.

Cyano and amide are important functionalities in medicinal chemistry, and organic chemistry transformations. We have devised a new, safe, and easy method for the synthesis of cyano and further amide using aldehyde via copper-mediated cyanation and amidation with ammonium acetate/iodine in DMF in a time-dependent manner. This approach efficiently converts aryl/alkyl/hetero aldehydes into their corresponding cyano which can be isolated after 3 h and/or if continued for 24 h then in-situ transformed into amide derivatives. Herein cupric acetate plays the role of coordinator, ammonium acetate is the nitrogen source, while DMF serves as a carbon source. We did easy and safe cyanation to explore the synthesis of varieties of cyano in 69–86% yields and respective amide derivatives in 58–75% yields. Thus, this process can serve the dual advantage in the synthesis of cyano and amides bioactive scaffold using respective aldehyde.

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Herein, a newly synthesized intermediate, piperazine-based Schiff base (PBSB) gas sensor was fabricated by the Schiff base condensation of amino functionalized methylpiperazine with aromatic aldehyde containing nitro substituent. This organic sensor material was structurally identified with spectroscopic techniques such as FTIR, HRMS, ¹H- and ¹³C-NMR. The designed sensor candidate was explored for its optical response to chlorinated volatile organic compounds, namely trichloroethylene, dichloromethane and chloroform in the light of structure–property relationship investigation by using surface plasmon resonance (SPR) technique. The results showed that Schiff bases could be candidates for chlorinated vapour sensing materials with their good response and reversibility. Concordantly, compound PBSB exhibited good response against chlorinated solvent vapours aided by the electron-withdrawing group on benzene ring that promoted better intermolecular interactions and opened up a new strategy to create a novel set of responsive materials for gas sensing applications. In addition, the adsorption kinetics of SPR data obtained from PBSB spun film on exposure to these chlorinated vapours at different concentrations was also evaluated using the Elovich Model. The values of the initial adsorption rate, a and Elovich constant, b were analysed depending on the concentration values and the highest values were obtained for dichloromethane between 372.92 and 4377.53 ppm/mm².

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In this study, we show that the use of a mixture of melamine and oxalic acid during the synthesis of acid-treated crystalline graphitic carbon nitride samples significantly enhances its photocatalytic activity in VOCs destruction processes. The rate of photocatalytic ethanol destruction with the participation of modified crystalline graphitic carbon nitride obtained under optimal conditions is 67.1 μmol h⁻¹, which is almost twice higher than sample synthesized in the absence of oxalic acid, and is two orders of magnitude higher than the activity of bulk g–C₃N₄. The synthesized materials were characterized using XRD, FT-IR, UV–Vis, PL, SEM, and EDXA methods. The high activity of the modified carbon nitride samples is attributed to increased light absorption in the visible region of the spectrum and better crystallinity, which can lead to more efficient separation and transport of photogenerated charges. To our knowledge, the effect of the simultaneous use of melamine and oxalic acid for obtaining acid-treated crystalline graphitic carbon nitride is, shown for the first time.

In this paper, the design, synthesis and catalytic application of a magnetic covalent organic framework modified with sulfonic acid (Fe₃O₄@COF-SO₃H) in the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives, were studied. The structure of the prepared catalyst was confirmed by various techniques including Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy, thermo-gravimetric analysis, field emission scanning electron microscopy, vibrating-sample magnetometer and Brunauer–Emmett–Teller porosimetry. The structure of the prepared derivatives was also confirmed using FT-IR and nuclear magnetic resonance (¹HNMR and ¹³CNMR) spectroscopy. Facile synthesis, solvent-free conditions, high yield, short reaction time, eco-friendly procedure, and straightforward work-up are among the advantages of this research.

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The synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) was made by utilizing newly synthesized heterogeneous mixed ligand-based Ni-phen MCM-41 catalyst with variety of aryl aldehydes (viz. electron donating, electron withdrawing, fused, disubstituted and unsaturated substituents), ethylacetoacetate, urea and ethanol as a solvent by using two different energy sources: conventional and ultrasonication methods. The effectiveness of the two methods was compared and found that the formation of Biginelli products in ultrasonication method (65–92% yield at 60 °C, 45 min) is better than the conventional method (63–90% yield at 78 °C, 2 h) by yield, temperature and time of the reaction. The formation, heterogeneous nature and morphology of the catalyst have been characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA) and N₂ adsorption–desorption isotherm (BET) techniques. Moreover, the catalyst was recoverable, reusable and very much efficient for three consecutive runs without any significant loss of its catalytic activity. The heterogeneity nature of the recovered catalyst was checked by hot filtration test.

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Bio-oil obtained through the gasification or pyrolysis of biomass is a renewable energy source with the potential to be used in motor vehicles. However, when the properties of bio-oil are compared to crude oil, bio-oil is observed to have high oxygen content and acidity. The aim of this study is to enhance the physical properties of bio-oil and produce new alternative fuels to crude oil. For this purpose, nickel and cobalt-incorporated mesoporous HZSM-5 catalysts have been synthesized. The synthesized catalysts were characterized by X-ray diffraction, N₂ adsorption–desorption, Scanning electron microscopy energy dispersive spectroscopy, Inductively coupled plasma optical emission spectroscopy, Fourier-transformed infrared spectroscopy, and thermogravimetric/differential thermal analysis. In the study, formic acid, furfural, and hydroxypropanone were used as model components. To enhance catalyst activity, nickel was loaded onto the HZSM-5 catalyst. However, during biofuel production, a significant amount of coke was formed as a by-product. Therefore, cobalt was impregnated to reduce coke formation. In the activity test studies, a conversion in the range of 77–84% was achieved with HZSM-5 catalysts. Nickel addition increased the paraffin and olefin content in the biofuel along with bio-oil conversion. The maximum paraffin selectivity (97%) was provided with the 5Ni@HZSM-5 catalyst. However, the highest biofuel selectivity (77.5%) with the minimum coke formation (4%) was observed with the 5Co-5Ni@HZSM-5. In the study, the regeneration and long-term catalytic activity were also investigated, and the results showed that 5Co-5Ni@HZSM is an attractive catalyst for biofuel production from bio-oil.

Owing to the low energy consumption and few by-products, toluene alkylation is regarded as a promising way to produce p-xylene. The zeolites with the characteristics of 10-MR were usually employed to catalyze the toluene alkylation after being modified. However, the catalyst activity is liable to sharp decrease by common modifying strategies. In this study, the alkylation of toluene with dimethyl carbonate was catalyzed by the MCM-22 zeolites with selective dealumination and silanization treatment. The Al sites on the MCM-22 external surface were first eliminated by oxalic acid, and then trimethylsilyl groups were grafted at the external surface of MCM-22 by bonding with Si–OH formed from dealumination. This modification strategy can not only reduce the Brønsted acid sites on the external surface and narrow the pore entrance size but also retain more internal active sites, leading to improving PX selectivity without a significant decrease in activity. Compared to parent MCM-22, the PX selectivity was doubled, and the toluene conversion only decreased from 39 to 34% over 200-DeMCM-22 catalyst at 400 °C.

In this study, we have investigated a strategy for designing some novel pyrazoline-thiazole hybrids containing azo moiety. The synthesized compounds were structurally characterized and their antibacterial activity was in vitro evaluated against gram-negative and gram-positive bacteria using the inhibition zone method. The antibacterial activity of the tested compounds was moderate to good. Compound 12c showed the best activity compared to the standard drug (Ampicillin) against S. aureus and E. coli at the concentration of 0.16 mg/mL, with the highest inhibition zone diameters of 34 mm and 37 mm, respectively. Moreover, in silico molecular docking and ADME profile studies were investigated in order to understand the binding affinity and interactions along with the ADME properties of all designed hybrids. Additionally, Density functional theory (DFT) calculations were carried out at the B3LYP/6-311G++ level of theory. The study involved an examination of the optimized geometry, molecular electrostatic potential map, and the HOMO → LUMO electronic energy gap. In accordance with the findings, the newly synthesized hybrids could be beneficial for medicine and exhibit antibacterial activity.