Preparation and characterization of a silica-based magnetic nanocomposite and its application as a recoverable catalyst for the one-pot multicomponent synthesis of quinazolinone derivatives

A vitamin C-based natural deep eutectic solvent for the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives

Efficient and green protocols were reported to synthesize 2,3-dihydroquinazolin-4(1H)-one derivatives in natural deep eutectic solvent (NADES). NADES was prepared from ascorbic acid (AA) and choline chloride (ChCl) with reduced or null toxicity, biocompatibility, and low cost. The ChCl/AA NADES was successfully used in the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives via the condensation reaction of aldehydes with 2-aminobenzamide and the three-component reactions of aldehydes, isatoic anhydrides and ammonium salts under solvent-free conditions. The scope of this method was evaluated by employing various aromatic, heterocyclic, and aliphatic aldehydes. The desired products were achieved in 85-97 % yield in a short reaction time. Also, the deep eutectic solvent ChCl/AA showed good recyclability and reusability.

Preparation of O-g-C3N4 nanowires/Bi2O2CO3 porous plate composite photocatalysts for the efficient degradation of tetracycline hydrochloride in wastewater

Both g-C3N4 and Bi2O2CO3 are good photocatalysts for the removal of antibiotic pollutants, but their morphological modulation and catalytic performance need to be further improved. In this study, the calcination-hydrothermal method is used to prepare a O-g-C3N4@Bi2O2CO3 (CN@BCO) composite photocatalyst from dicyandiamide and bismuth nitrate. The prepared catalyst is characterized through various methods, including X-ray diffraction (XRD) and transmission electron microscopy (TEM). Further, the effects of different parameters, such as catalyst concentration and initial pH of the reaction solution, on its photocatalytic activity are investigated. The results show that the CN@BCO sample achieves an optimal degradation rate of 98.1% for tetracycline hydrochloride (TCH) with a concentration of 20 mg/L and a removal rate of 69.4% for total organic carbon (TOC) at 40 min. The quenching experiments show that ·O2-, h+, and ·OH participate in the photocatalytic process, with ·O2- being the most dominant active species. The toxicity of the predicted TCH degradation intermediates is analyzed using Toxicity Estimation Software Tool (TEST). Overall, the CN@BCO composite exhibits excellent photocatalytic performance, making it a promising candidate for environmental purification and wastewater treatment.

Fe3O4@Sap/Cu(ii): an efficient magnetically recoverable green nanocatalyst for the preparation of acridine and quinazoline derivatives in aqueous media at room temperature

Saponin, as a green and available phytochemical, was immobilized on the surface of magnetite nanoparticles then doped with Cu ions (Fe3O4@Sap/Cu(ii)) and used as an efficient nanocatalyst for the synthesis of quinazoline and acridine derivatives, due to their high application and importance in various fields of science. Different spectroscopic and microscopic techniques were used for the catalyst characterization such as FT-IR, XRD, FE-SEM, EDX, TEM, TGA, VSM, BET, DLS, CV, and XPS analyses. All characterization data were correlated with each other so that the structure of the catalyst was accurately characterized. The reactions were performed in the presence of a low amount of Fe3O4@Sap/Cu(ii) (0.42 mol%) as a green catalyst in water over a short period of time. The results show well the effective role of saponin in solving the problem of mass transfer in aqueous medium, which is the challenge of many organic reactions in aqueous medium and in the presence of heterogeneous medium. High catalytic activity was found for the catalyst and high to excellent efficiency was obtained for all quinazoline (68-94% yield) and acridine (66-97% yield) derivatives in short reaction times (less than 1 hour) under mild reaction conditions in the absence of any hazardous or expensive materials. There is not any noticeable by-product found whether for acridine or quinazoline derivatives, which reflects the high selectivity. Two reasonable mechanisms were proposed for the reactions based on observations from control experiments as well as literature reports. The catalyst could be easily recovered magnetically for at least six consecutive runs with insignificant reactivity loss.

Recent developments in the nanomaterial-catalyzed green synthesis of structurally diverse 1,4-dihydropyridines

1,4-Dihydropyridine (1,4-DHP), a privileged heterocyclic scaffold, has been extensively utilized in various biological and therapeutic applications. In this review article, we discussed the role of different nano-catalysts, nanoflakes, nanocomposites, and other green-supported nanomaterials in the synthesis of a biologically active and vital pharmaceutical precursor 1,4-DHP and its derivatives such as polyhydroquinoline, benzopyranopyridines, and dihydropyridine since 2015. It is evident that although the use of various tailored nanostructures under different conditions to optimize the synthesis of 1,4-DHP and its compounds has provided sustainable and efficient proposals, yet the development of greener practices in the synthesis of 1,4-DHPs, which can be applied to design new synthetic routes and sequences in process development, is a far-reaching task to be accomplished.

Single pot multicomponent approaches using different nanomaterials as green catalysts for synthesis of 1,4-dihydropyridine (1,4-DHP), a privileged heterocyclic scaffold with vital biological and therapeutic applications are reviewed.

Probing the catalytic activity of highly efficient sulfonic acid fabricated cobalt ferrite magnetic nanoparticles for the clean and scalable synthesis of dihydro, spiro and bis quinazolinones

An exceptionally productive, rapid, simple, and eco-friendly approach for the synthesis of 2,3-dihydroquinazolin-4(1H)-one has been developed utilizing acidic magnetically retrievable cobalt ferrite nanoparticles (CFNP@SO3H).

Preparation of Fe3O4/SiO2/TiO2/CeVO4 Nanocomposites: Investigation of Photocatalytic Effects on Organic Pollutants, Bacterial Environments, and New Potential Therapeutic Candidate Against Cancer Cells

The new nanocomposite with various molar ratios along with magnetic properties was fabricated via precipitation (assisted by ultrasonic) procedure. The photocatalytic effects of methylene blue (∼90% degradation for optimized sample in 100 min) for finding the optimized sample performed under visible light irradiation. Moreover, the photo-antibacterial impacts of bacteria culture environments were found with an optimized sample that had effective destruction of bacteria in comparison to control group. The cytotoxicity properties of panc1 cells and magnetic behaviors of the obtained nanomaterials were evaluated and its IC50 was about 500 mg/L. As an initial step, the structural, morphological and magnetic characteristics of the fabricated nanocomposites were evaluated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and MAP, UV-visible diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometry (VSM) approaches. Based on SEM results, the size of nanoparticles in fabricated nanocomposite was nearly 50-70 nm for Fe3O4/SiO2/TiO2 and 80-100 nm for Fe3O4/SiO2/TiO2/CeVO4. XRD results showed that desired nanocomposites were truly synthesized without any impurities.

Comparative study of ASNase immobilization on tannic acid-modified magnetic Fe3O4/SBA-15 nanoparticles to enhance stability and reusability

Herein, we report the preparation of tannic acid-modified magnetic Fe₃O₄/SBA-15 nanoparticles and their application as a carrier matrix for immobilization of ASNase, an anticancer enzyme-drug.

Green synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazoles] using Fe3O4@l-arginine as a robust and reusable catalyst

The synthesized Fe3O4@l-arginine showed strong catalytic performance in the one-pot synthesis of spiropyranopyrazoles via the reactions of hydrazines, β-keto esters, isatins, and malononitrile or ethyl cyanoacetate under solvent-free conditions. The biologically active heterocyclic compounds including spiropyranopyrazole derivatives were efficiently synthesized in short reaction times and excellent yields in the presence of Fe3O4/l-arginine at room temperature. The highlighted features of the Fe3O4@l-arginine nanocomposite are highly stable, easy to separate, low loading, cost-effective with easy preparation and reusability of the catalyst. The heterogeneous nanocomposite was fully characterized by SEM, EDX, FT-IR, XRD and TEM analysis.

Green Fabrication of Cobalt NPs using Aqueous Extract of Antioxidant Rich Zingiber and Their Catalytic Applications for the Synthesis of Pyrano[2,3-c]pyrazoles

AIM AND OBJECTIVE

In this study, biological synthesis of cobalt nanoparticles was developed in the presence of ginger extract as the reducing and capping agent through the simple and convenient co-precipitation method.

MATERIALS AND METHODS

The as-synthesized cobalt nanoparticles were characterized by X-ray diffraction (XRD), scanning Electron Microscopy (SEM), spectra energy dispersive analysis of Xray (EDS), Fourier transform infrared (FT-IR), and vibrating sample magnetometer (VSM) techniques. According to the vibrating sample magnetometer, cobalt nanoparticles show paramagnetic behaviour at room temperature. Furthermore, the effect of ginger extract concentration on the UV-Vis absorbance of Co nanoparticles was investigated. Based on the UVVis absorbance spectra, increasing ginger extract concentration causes particle size to decrease. In addition, the catalytic performance of the synthesized cobalt nanoparticles was investigated in the preparation of pyrano[2,3-c]pyrazoles via one-pot four-component reactions of aryl aldehydes, hydrazine hydrate, malononitrile and diethyl acetylenedicarboxylate.

RESULT AND CONCLUSION

The prepared pyrano[2,3-c]pyrazole derivatives were obtained in high yields within short reaction times and the nanocatalyst was easily separated using an external magnet and reused for several times with no significant loss of its activity.

Metal-Free One-Pot Four-Component Cascade Annulation in Ionic Liquids at Room Temperature: Convergent Access to Thiazoloquinolinone Derivatives

An efficient, eco-friendly, and highly convergent one-pot route to privileged thiazoloquinolinone derivatives has been developed via four-component cascade coupling (4CCC) of α-enolic dithioesters, cysteamine/2-aminothiophenols, aldehydes, and cyclic 1,3-diketones in recyclable [EMIM][EtSO₄] ionic liquid at room temperature for the first time. The reaction proceeds via a N,S-acetal formation, Knoevenagel condensation, aza-ene reaction, imine-enamine/keto-enol tautomerization, and intramolecular N-cyclization cascade sequence. The merit of the protocol is highlighted by its efficacy of forming consecutive five new bonds (two C-C, two C-N, and one C-S) and two rings with all reactants being efficiently utilized. The operational simplicity, sustainability, mild conditions, excellent yields, tolerance of wide functional groups, and avoidance of expensive/toxic reagents are additional attributes to this domino four-component protocol. Notably, the products were easily separated from the ionic liquid, and thus the ionic liquid obtained was reused four times without considerable loss of any activity.

2,3-Dihydroquinazolin-4(1H)-one as a privileged scaffold in drug design

2,3-Dihydroquinazolin-4-one (DHQ) belongs to the class of nitrogen-containing heterocyclic compounds representing a core structural component in various biologically active compounds. In the past decades, several methodologies have been developed for the synthesis of the DHQ framework, especially the 2-substituted derivatives. Unfortunately, multistep syntheses, harsh reaction conditions, and the use of toxic reagents and solvents have limited their full potential as a versatile fragment. Recently, use of green chemistry and alternative strategies are being explored to prepare diverse DHQ derivatives. This fragment is used as a synthon for the preparation of biologically active quinazolinones and as a functional substrate for the synthesis of modified DHQ derivatives exhibiting different biological properties. In this review, we provide a comprehensive assessment of the synthesis and biological evaluations of DHQ derivatives.