Research on Chemical Intermediates最新文献

Biscoumarin derivatives are an important group of bis-heterocyclic compounds that have attracted much attention due to their useful biological and medicinal properties. Caffeine was extracted from black tea and characterized using infrared (IR), ¹H, and ¹³C nuclear magnetic resonance (NMR) spectra. The extracted caffeine was used as an efficient, useful, and environmentally friendly organo-catalyst to synthesize biscoumarins. Optimizing the reaction conditions showed that 10 mol% of catalyst, water, and 80 °C is enough to synthesize the desired bis-heterocyclic products. Under the optimized reaction conditions, the pseudo-three component reaction of aryl/hetaryl aldehydes with 4-hydroxycoumarin was used to synthesize 3,3′-(arylmethylene)-bis(4-hydroxycoumarins. The 3,3′-(arylmethylene)-bis(4-hydroxycoumarin)s have been synthesized in good to excellent reaction yields and relatively shorter reaction times. The synthesis may proceed via a Knoevenagel condensation, Michael addition, and tautomerization. Some of the advantages of this method include the ease of separation of products, utilizing available starting materials, and the relatively simple implementation of the reaction. This work is also important from the point of view of green chemistry and economic savings. Furthermore, the method works well for substituted benzaldehydes containing electron-donating and electron-withdrawing groups and is compatible with heteroaryl aldehydes such as thiophene-2-carboxaldehyde. The structure of the synthesized biscoumarins was characterized using melting point measurements and spectroscopic data.

In this study, a DABCO-based ionic liquid containing cobalt metal ([(DABCO)₂C₃H₅OH]·CoCl₄) was successfully synthesized through a simple method combined with DABCO, 1,3-dichloropropan-2-ol and CoCl₂. The structure of this reagent was investigated via various analytical methods including Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA), X-ray diffraction pattern (XRD), energy dispersive X-ray analysis (EDX), and field emission scanning electron microscopy (FESEM). The catalytic performance of the prepared Lewis acidic catalyst was evaluated for the reduction of nitroarenes, and aromatic aldehydes and also one-pot reductive acetylation of aldehydes using NaBH₄ and CH₃COCl as the hydrogen donor and acetylating agent, respectively. Ease of preparation, reusability of the catalyst, short reaction times and excellent yields of the obtained compounds are among the salient features of this process.

A series of 3d transition metal complexes with a general formula [(L)₂ M(X)].nCl was synthesized by using bis(pyrazolyl)methane as a ligand in a 2:1 stoichiometric ratio. These compounds were characterized using appropriate spectroscopic and analytical techniques, i.e. ¹H NMR, ¹³C NMR, FT-IR, UV–Vis spectroscopy, and TG analysis. The crystal structures of the complexes (C4 and C5) were determined using the single-crystal X-ray diffraction technique. All the metal complexes demonstrated octahedral geometry with two bis(pyrazolyl)methane ligands and water/chloride co-ligands. These metal complexes were tested against gram-positive and gram-negative bacteria to investigate their antibacterial efficiency. Among these metal complexes, the copper complex C5 showed good antibacterial activity and the lowest MIC values towards all the bacterial strains. Further, the complex C5 showed stronger binding affinity towards the target proteins of the pathogens, as revealed by molecular docking studies.

Here in this work we designed and synthesized a series of new sulfonylurea derivatives bearing biphenyl moieties whose structures were confirmed by ¹H-NMR, ¹³C-NMR, IR and MS. The cytotoxicity of these compounds was first evaluated by MTT assay in J774A.1 cells and then their inhibitory activities against NLRP3 activation were evaluated in vitro in both J774A.1 and RAW264.7 cell lines initiated by LPS and ATP. The results showed that compound 10n (Sodium{(2-(nathphalen-2-yl) phenyl) carbamoyl} ((4-(2-hydroxypropan- 2-yl) furan-2-yl) sulfonyl) amide) had a good in vitro safety profile and a significant inhibitory effect on NLRP3 activation with an IC₅₀ value of 100.7 nM in RAW264.7 cells, which was only slightly weaker than MCC950 with an IC₅₀ value of 49.24 nM. Further computational studies (molecular docking, RMSD, RMSF, binding energy and DCCM analysis) indicated that 10n could be accommodated in the binding site of NLRP3 and strongly interact with NLRP3. Compound 10n has the potential to be further developed as a promising NLRP3 inhibitor.

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In this study, a copper iodide catalyst immobilized on layered double hydroxides and covered with a 1,3-benzenedisulfonylamide ligand was successfully synthesized. This catalyst was used for the eco-friendly synthesis of various substituted imidazole derivatives through a one-pot three-component reaction, demonstrating remarkable activity and selectivity. Key benefits of this approach include high product yields, rapid reaction kinetics, low reaction temperature, solvent-free conditions, generation of novel products, and straightforward purification methods. Additionally, the catalyst exhibits simple recyclability (up to 4 cycles), further enhancing its practical appeal.

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This study aimed to explore the extracts of Castanea mollissima Blume, 1851 as rich sources of enzyme inhibitors targeting type 2 diabetic (T2D) drugs. It was proved that the enzyme inhibitor with moderate effect against α-amylase and high inhibition against α-glucosidase may be a potential candidate for T2D management. Among the parts used of C. mollissima, the trunk bark extract demonstrated moderate pancreatic α-amylase inhibitory activity and a high inhibitory effect against α-glucosidase from rat with the IC₅₀ inhibition values of 371.23 and 212.79 μg/mL, respectively. Acarbose—a commercial antidiabetic compound with testing IC₅₀ of 24.01 and 192.35 μg/mL against α-amylase and α-glucosidase, respectively. Notably, the potent mammalian α-glucosidase inhibitory effect of the C. mollissima trunk bark extract collected in Vietnam was reported for the first time. Nineteen compounds (named 1–19) were detected and identified from the C. mollissima trunk bark extract using GCMS and HPLC analyses. Based on GCMS analysis, 9 volatiles were identified (1–9), of these, compounds 1, 4, and 9 were found as major volatiles with areas of 11.44, 13.5 and 45.27%, respectively. The utilization of HPLC techniques resulted in the detection and identification of 3 phenolic (10, 12, 15) and 7 flavonoid compounds (11, 1 3, 14, 16, 17, 18, 19). Of these, compounds 11, 12, 13, 14, 15, and 17 were found to contain in the C. mollissima trunk bark extract with high contents of 120.734, 40.373, 79.826, 43.845, 57.933, and 19.145 μg/mg of dried extract, respectively. The docking result indicated that most major compounds (1, 4, 9, 11, 12, 14, and 17) showed effective binding to α-glucosidase with good binding energy and acceptable RMSD values. In addition, almost all the identified compounds possessed drug properties and showed non-toxic for human use via Lipinski’s rule of five and ADMET analyses.

Herein, we have synthesized copper oxide nanoparticles (CuONPs) using an aqueous pod extract of Acacia concinna (A. concinna) and analyzed their catalytic activities. The phytochemicals in the pod extract of A. concinna were used as a reducing and stabilizing agent and CuSO₄·7H₂O as a precursor for forming CuONPs. The biosynthesized CuONPs were characterized using UV–visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM) for structural and morphological analysis. The synthesis of CuONPs was confirmed by the UV absorption peak at 330 nm and XRD analysis. TEM analysis has been representing the CuO nanospheres with an average size of 29 nm. The newly synthesized CuONPs exhibit greater antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The highest efficacy of biosynthesized CuONPs (200 µg/mL) was observed against S. aureus with a 36.5 mm zone of inhibition. Biosynthesized CuONPs are a basic, highly efficient, heterogeneous, and green recyclable catalyst for the multicomponent synthesis of 4H-benzo[b]pyran derivatives. Tetra-hydrobenzo[b]pyran derivatives can be synthesized through a three-component reaction involving an aldehyde, malononitrile, and either 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione, conducted at room temperature. This synthetic method provides several advantages such as simple work-up procedures, short reaction time, minimal byproducts, and high yields of products.

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This study includes the synthesis of 11 different calixarene derivatives, the preparation of thin film sensors on quartz crystal microbalance (QCM) crystals, and the specification of sensor-analyte pairs by examining the sensing properties of these sensors against different phenolic compounds such as p-nitrophenol (PNP), phenol (PHE), p-chlorophenol (PCP), and m-nitrophenol (MNP) in the aqueous medium. For this purpose, calixarene derivatives with different structures were first synthesized and characterized using spectroscopic methods such as Proton nuclear magnetic resonance (¹H-NMR) and Fourier-transform infrared spectroscopy (FTIR). Detection studies were carried out for proposed phenolic compounds with calixarene-based QCM sensors obtained by electrospinning. At the beginning of the experiments, sensor-analyte pairs were determined according to the values at which the highest sensor frequencies were observed. Therefore, according to the highest sensor responses towards 5 × 10^–5 M analytes, the sensor-analyte pairs were determined as QCM-5 for PNP (17.8 Hz) and MNP (3.8 Hz). Also, for PHE and PCP, the highest responses were observed as 4.1 Hz and 4.0 Hz in the QCM-11 and QCM-1 sensors, respectively. In further experiments, determined sensor-analyte pairs were tested at different analyte concentrations. In addition, the limits of detection (LOD) of the sensors were calculated from different analyte concentration studies such as 0.580 (QCM-5), 0.659 (QCM-11), 0.490 (QCM-1), and 0.466 (QCM-5) mM against PNP, PHE, PCP, and MNP, respectively. Interactions between sensor-analyte pairs were evaluated in terms of adsorption kinetics. It was observed that the relationships between the sensor responses and the analyte concentration were highly consistent with the Freundlich isotherm. In addition, repeatability and stability tests of the sensors were performed, and it was observed that they exhibited good repeatability and stability properties. Finally, selectivity between analytes was assessed, and the highest selectivity was observed as with the QCM-4 sensor versus p-nitrophenol. It was found that the selectivity of the sensor to PNP was 21.1 times compared to PHE and PCP and 74 times compared to MNP.

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Three pyrrolo[3, 2-b]pyrrole compounds (Py–CF₃–H, Py–CF₃–CH₃ and Py–CF₃–OCH₃) were prepared as radical photoinitiators for visible light radical photopolymerization. Radical photopolymerization using the Py–CF₃–H initiator-induced TMPTA system achieved a peak conversion rate of 72% for C=C double bonds. The effect of changes in the electronic structure on the photoinitiation ability of the three photoinitiators was studied using spectroscopic measurements and theoretical calculations. The generated free radicals were detected using electron paramagnetic resonance (EPR). The synthesized photoinitiators matched the 405 nm LED. Under steady photolysis at 405 nm, the maximum absorption peaks decreased rapidly after exposure to light, and a new blue-shifted peak appeared. The end groups on the phenyl at 1,4 positions of the pyrrolo[3,2-b]pyrrole core considerably influenced the charge surrounding the central core, according to the electrostatic potential (ESP) results. The –H on 1,4-phenyl provides a less negative charge on the fused pyrrole core compared to the –CH₃ and –OCH₃. Thus, this work provides an experimental foundation for investigating pyrrole-based photoinitiators in polymer curing.

A copper coordinated L-ascorbic acid (Cu@AACP) metal–organic framework was synthesized and characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), wavelength dispersive X-ray spectroscopy (WDX), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The BET method was used to investigate the textural characteristics of Cu@AACP, including surface area, pore diameter and total pore volume. The SEM analysis was used to investigate the morphology and size of Cu@AACP particles. AAS, WDX and EDS techniques were used to investigate the elemental content of Cu@AACP. The TGA analysis was used to investigate the presence of solvents or moisture, thermal stability and organic–inorganic content of catalyst. The FT-IR spectroscopy was used to the characterization of functional groups in the structure of the materials. The XRD pattern was used to investigate the crystalline phase of the catalyst. The results of the analyses confirmed the successful synthesis of copper MOF of L-ascorbic acid (Cu@AACP). The catalytic performance of Cu@AACP was examined in synthesizing of 2, 3-dihydroquinazolin-4(1H)-ones (through condensation of aldehydes and anthranilamide in ethanol at 80 °C) and polyhydroquinolines (through condensation of aldehydes, dimedone, ammonium acetate and ethyl acetoacetate in ethanol at 80 °C). The reaction conditions for the synthesis of 2, 3-dihydroquinazolin-4(1H)-ones and polyhydroquinolines were optimized, where the best results were obtained in ethanol solvent at 80 °C in the presence of 6 mg of Cu@AACP as catalyst. The results show that an improved product yield is obtained between 84 and 95%. Recycle test of the catalyst confirmed that the heterogeneous catalyst exhibited good catalytic stability, efficiency and very high activity in successive runs because of its unique pore network. To show the stability of Cu@AACP nanocatalyst after recycling, the recovered catalyst was characterized by AAS, FE-SEM, EDS and FT-IR techniques.