Synthesis, antibacterial activities evaluation, and docking studies of some 2-substituted-3-(phenylamino)-dihydroquinazolin-4(1 H )-ones

One-pot synthesis of quinazolinone heterocyclic compounds using functionalized SBA-15 with natural material ellagic acid as a novel nanocatalyst

The nanoporous compound SBA-15 was functionalized using (3-aminopropyl)trimethoxysilane (APTES). Then the obtained product was modified with ellagic acid (ELA), a bioactive polyphenolic compound. The structure of the prepared nanoporous composition SBA-15@ELA was extensively characterized and confirmed by various techniques, such as Fourier-transform infrared (FT-IR) spectroscopy, Energy dispersive X-ray (EDX) elemental analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherms (BET). The novel, recoverable, heterogenous SBA-15@ELA nanoporous compound was used to investigate its catalytic effect in the synthesis of 4-oxo-quinazoline derivatives (19 examples) with high yields (78-96%), as an important class of nitrogen-containing heterocyclic compounds. The use of an inexpensive mesoporous catalyst with a high surface area, along with easy recovery by simple filtration are among the advantages of this catalysis research work. The catalyst has been used in at least 6 consecutive runs without a significant loss of its activity.

Application of Deep Eutectic Solvents in the Synthesis of Substituted 2-Mercaptoquinazolin-4(3H)-Ones: A Comparison of Selected Green Chemistry Methods

In this study, deep eutectic solvents (DESs) were used as green and eco-friendly media for the synthesis of substituted 2-mercaptoquinazolin-4(3H)-ones from different anthranilic acids and aliphatic or aromatic isothiocyanates. A model reaction on anthranilic acid and phenyl isothiocyanate was performed in 20 choline chloride-based DESs at 80 °C to find the best solvent. Based on the product yield, choline chloride:urea (1:2) DES was found to be the most effective, while DESs acted both as solvents and catalysts. Desired compounds were prepared with moderate to good yields using stirring, microwave-assisted, and ultrasound-assisted synthesis. Significantly, higher yields were obtained with mixing and ultrasonication (16-76%), while microwave-induced synthesis showed lower effectiveness (13-49%). The specific contribution of this research is the use of DESs in combination with the above-mentioned green techniques for the synthesis of a wide range of derivatives. The structures of the synthesized compounds were confirmed by 1H and 13C NMR spectroscopy.

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.

Synthesis, Cytotoxic, and Antibacterial Evaluation of Quinazolinone Derivatives with Substituted Amino Moiety

A series of novel quinazolinone derivatives containing a substituted amino moiety were synthesized, evaluated for their cytotoxic and antibacterial activities. The results of MTT assay showed that all synthesized target compounds 5A - 5O showed potent cytotoxicity against SGC-7901 (IC₅₀ , 0.72 - 1.41 μm). Moreover, the compounds 5D, 5I, and 5K showed better selectivity as compared with positive controls pemetrexed and MTX due to weak cytotoxicity against normal tissue cell line HUVSMC. Among synthesized compounds, the compounds 5E, 5J, 5L, and 5N showed broad-spectrum cytotoxic activities against at least four cancer cell lines at a micromolar level. The results of antibacteria evaluation revealed that all synthesized compounds showed good to moderate antibacterial activities against Gram-negative bacteria Escherichia coli. Among them, the MIC values of the compounds 5C, 5F, and 5M were 0.31 μg/mL.

Ultrasonic treatment of CoFe2O4@B2O3-SiO2 as a new hybrid magnetic composite nanostructure and catalytic application in the synthesis of dihydroquinazolinones

New hybrid magnetic composite nanostructure are prepared via ultrasonic treatment by glass-ceramic method, characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), energy-dispersive X-ray (EDX), element distribution image (EDX mapping), thermal gravimetric analysis (TGA)/differential thermal analysis (DTA) and N₂ adsorption-desorption by Brunauer-Emmett-Teller (BET) analyses. Then, the catalytic activity of the prepared CoFe₂O₄@B₂O₃-SiO₂ nanoparticles was tested in the synthesis of 2-substituted-3-(phenylamino)-dihydroquinazolin-4(1H)-ones in deep eutectic solvent (DES) based on choline chloride as an eco-friendly and recyclable media. This novel protocol offers several advantages such as high yields (70-93%), short reaction times (10-20min), environmentally-friendly reaction media, easily isolation of the products, simple preparation and recoverability of the nanocatalysts (at least 5 times), recyclability of the solvents from the reaction mixture without use of hazardous volatile organic solvent. The catalyst was readily recycled by the use of an external magnetic field and could be reused several times without significant loss of activity or mass. The saturation magnetization of CoFe₂O₄@B₂O₃-SiO₂ nanoparticles was 8.97emug^-1. Their average size distribution was about 12.5nm. DES was a mixture of choline chloride and urea that was recovered from the filtrate by evaporating the water under vacuum.

One-pot synthesis and antifungal activity against plant pathogens of quinazolinone derivatives containing an amide moiety

An efficient one-pot, three-component synthesis of quinazolinone derivatives containing 3-acrylamino motif was carried out using CeO2 nanoparticles as catalyst. Thirty-nine synthesized compounds were obtained with satisfied yield and elucidated by spectroscopic analysis. Four phytopathogenic fungi were chosen to test the antifungal activities by minimum inhibitory concentration (MIC) method. Compounds 4ag, 4bb, 4bc showed broad antifungal activities against at least three fungi, and dramatic effects of substituents on the activities were observed. Docking studies were established to explore the potential antifungal mechanism of quinazolinone derivatives as the chitinase inhibitors, and also verified the importance of the amide moiety.