CuO nanoparticles catalyzed simple and efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones under ultrasound irradiation in aqueous ethanol under ultrasound irradiation in aqueous ethanol

2,3-Dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones as broad-spectrum cytotoxic agents and their impact on tubulin polymerisation

Tubulin plays a central role in mitosis and has been the target of multiple anticancer drugs, including paclitaxel. Herein two separate families of 2,3-dihydroquinazoline-4(1H)-ones and quinazoline-4(3H) ones, comprising 57 compounds in total, were synthesised. Screening against a broad panel of human cancer cell lines (HT29 colon, U87 and SJ-G2 glioblastoma, MCF-7 breast, A2780 ovarian, H460 lung, A431 skin, Du145 prostate, BE2-C neuroblastoma, and MIA pancreas) reveals these analogues to be broad spectrum cytotoxic compounds. Of particular note, 2-styrylquinazolin-4(3H)-one 51, 2-(4-hydroxystyryl)quinazolin-4(3H)-one 63, 2-(2-methoxystyryl)quinazolin-4(3H)-one 64 and 2-(3-methoxystyryl)quinazolin-4(3H)-one 65 and 2-(naphthalen-1-yl)-2,3-dihydroquinazolin-4(1H)-one 39 exhibited sub-μM potency growth inhibition values. Of these 1-naphthyl 39 has activity <50 nM against the HT29, U87, A2780, H460 and BE2-C cell lines. Molecular modelling of these compounds, e.g. 2-(naphthalen-1-yl)-2,3-dihydroquinazolin-4(1H)-one 39, 2-(2-methoxystyryl)quinazolin-4(3H)-one 64, 2-(3-methoxystyryl)quinazolin-4(3H)-one 65, and 2-(4-methoxystyryl)quinazolin-4(3H)-one 50 docked to the known tubulin polymerisation inhibitor sites highlighted well conserved interactions within the colchicine binding pocket. These compounds were examined in a tubulin polymerisation assay alongside the known tubulin polymerisation promotor, paclitaxel (69), and tubulin inhibitor, nocodazole (68). Of the analogues examined, indoles 43 and 47 were modest promotors of tubulin polymerisation, but less effective than paclitaxel. Analogues 39, 64, and 65 showed reduced microtubule formation consistent with tubulin inhibition. The variation in ring methoxy substituent with 50, 64 and 65, from o- to m- to p-, results in a concomitant reduction in cytotoxicity and a reduction in tubulin polymerisation, with p-OCH350 being the least active in this series of analogues. This presents 64 as a tubulin polymerisation inhibitor possessing novel chemotype and sub micromolar cytotoxicity. Naphthyl 39, with complete inhibition of tubulin polymerisation, gave rise to a sub 0.2 μM cell line cytotoxicity. Compounds 39 and 64 induced G2 + M cell cycle arrest indicative of inhibition of tubulin polymerisation, with 39 inducing an equivalent effect on cell cycle arrest as nocodazole (68).

Carbazole and Quinazolinone Derivatives from a Fluoride-Tolerant Streptomyces Strain OUCMDZ-5511

Six new 9H-carbazole derivatives (1-6) and nine previously reported compounds (7-15) were isolated from a fermented solid medium of the Thailand mangrove-derived Streptomyces strain, OUCMDZ-5511, under fluoride stress. Compounds 2-5, 12, and 15 were exclusively present in the fluoride-supplemented fermentation medium, while compounds 7-9, 13, and 14 were newly discovered natural products. The molecular structures of the compounds were identified by a spectroscopic analysis. The new compound 2 displayed antiquorum sensing activity against Chromobacterium violaceum ATCC 12472 by reducing the violacein production and inhibiting the biofilm formation in a concentration-dependent manner. The study revealed that compound 2 could be a novel potential inhibitor of quorum sensing.

Novel quinazoline-chromene hybrids as anticancer agents: Synthesis, biological activity, molecular docking, dynamics and ADME studies

In this study, new quinazoline-chromene hybrid compounds were synthesized. The cytotoxic effects on cell viability of the hybrid compounds were tested against A549 human lung adenocarcinoma and BEAS-2B healthy bronchial epithelial cell lines in vitro. In addition, the ability of the active compounds to inhibit cell migration was tested. Molecular docking studies were performed to evaluate the ligand-protein interactions, and molecular dynamics simulations were performed to determine the interactions and stability of ligand-protein complexes. In silico absorption, distribution, metabolism, and excretion (ADME) studies were conducted to estimate the drug-likeness of the compounds. Compounds 4 (IC50  = 51.2 µM) and 5 (IC50  = 44.2 µM) were found to be the most active agents against A549 cells. They are found to be more selective against A549 cells than the reference drug doxorubicin. They also have the ability to significantly inhibit cell migration. They have the best docking scores against epidermal growth factor receptor (EGFR) (-11.300 and -11.226 kcal/mol) and vascular endothelial growth factor receptor 2 (VEGFR2) (-10.987 and -11.247 kcal/mol), respectively. In MD simulations, compounds 4 and 5 have strong hydrogen bond interactions above 80% of simulation times and showed a low ligand root mean square deviation (RMSD) around 2 Å. According to the ADME analysis, compounds 4 and 5 exhibit excellent drug-likeness and pharmacokinetic characteristics.

Acid/Base-Steered Cascade Cyclization: An Efficient One-Pot Access to Diverse Isobenzofuranone and Isoindolobenzoxazinone Derivatives

We herein report the acid/base-steered two distinct reaction pathways of 2-acylbenzoic acids with isatoic anhydrides. In the presence of Na₂CO₃, the cascade process consists of the cyclization of 2-acetylbenzoic acid and nucleophilic ring-opening reaction of isatoic anhydride to furnish isobenzofuranone derivatives with high efficiency. However, p-toluenesulfonic acid can promote the product isobenzofuranones to undergo sequential intramolecular rearrangment, nucleophilic addition and cyclization reaction to produce diverse isoindolobenzoxazinones in good yields. The synthetic utility of this method was further demonstrated by the gram-scale preparation of the desired products and the facile transformations of the resulting products.

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.

In situ fabrication of HDA-mediated NiFe–Fe2O3 nanorods: an efficient and recyclable heterogeneous catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones in water

A simple, facile and an effective route for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones via multi-component reactions using newly developed NiFe–Fe2O3 nanorods as heterogeneous catalysts.

Syntheses of 2-Iminoindolin-3-ones and 2-Alknyl-2,3-dihydroquinazolin-4(1H)-ones from 3-Diazoindolin-2-imines

3-Diazoindolin-2-imines reacted with nitrones to furnish 2-iminoindolin-3-ones through a Au(I)-catalyzed cascade oxygen transfer/imine exchange process. The prepared 2-iminoindolin-3-ones could be further transformed into 2-alknyl-2,3-dihydroquinazolin-4(1H)-ones through a Ag(I)-catalyzed reaction with terminal alkynes. A MeOH-triggered ring expansion mechanism involving cyclic iminium formation and nucleophilic addition is proposed for this novel alkynylation reaction. This two-step procedure provides a general and convenient approach to 2-alknyl-2,3-dihydroquinazolin-4(1H)-ones, which are privileged structures in medicinal chemistry.

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

Heterocycles have been found to be of much importance as several nitrogen- and oxygen-containing heterocycle compounds exist amongst the various USFDA-approved drugs. Because of the advancement of nanotechnology, nanocatalysis has found abundant applications in the synthesis of heterocyclic compounds. Numerous nanoparticles (NPs) have been utilized for several organic transformations, which led us to make dedicated efforts for the complete coverage of applications of metal nanoparticles (MNPs) in the synthesis of heterocyclic scaffolds reported from 2010 to 2019. Our emphasize during the coverage of catalyzed reactions of the various MNPs such as Ag, Au, Co, Cu, Fe, Ni, Pd, Pt, Rh, Ru, Si, Ti, and Zn has not only been on nanoparticles catalyzed synthetic transformations for the synthesis of heterocyclic scaffolds, but also provide an inherent framework for the reader to select a suitable catalytic system of interest for the synthesis of desired heterocyclic scaffold.

3,5-Bis(trifluoromethyl) Phenylammonium triflate(BFPAT) as a Novel Organocatalyst for the Efficient Synthesis of 2,3-dihydroquinazolin-4(1H)-one Derivatives

AIMS AND OBJECTIVES

A one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives by threecomponent cyclo-condensation of isatoic anhydride, aldehydes and amine or ammonium acetate has been developed using 3,5-Bis(trifluoromethyl) phenylammonium triflate (BFPAT) as a new organocatalyst.

MATERIALS AND METHODS

All of the obtained products are known compounds and identified by IR, 1HNMR, 13CNMR and melting points.

RESULTS

A wide variety of structurally different aldehydes reacted easily and rapidly to result in the relating 2,3-dihydroquinazolin-4(1H)-ones in good to excellent yield.

CONCLUSION

We have demonstrated an extremely effective and new process for synthesizing 2,3- dihydroquinazolin-4(1H)-ones employing BFPAT as a novel organocatalyst in one-pot fashion.

A Facile Microwave and SnCl2 Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

An elegantly simple, facile, and robust approach to a scaffold of biological importance, 2,3-dihydroquinazolin-4(1H)-ones, is reported. A catalytic 1% SnCl2/microwave-mediated approach afforded access to pure material, collected by cooling and filtration after 20-min microwave irradiation at 120°C. A total of 41 analogues were prepared in isolated yields of 17–99%. This process was highly tolerant of aliphatic, aromatic, heterocyclic, and acyclic aldehydes, but furan, pyrrole, and thiophene aldehyde reactivity correlated with propensity towards electrophilic addition and/or Diels–Alder addition. As a result, thiophene afforded high yields (80%) whereas pyrrole carboxaldehyde failed to react. With simple cinnamaldehydes, and in the SbCl3-mediated reaction, and with α,β-unsaturated aldehydes the equivalent quinazolin-4(3H)-ones, and not the 2,3-dihydroquinazolin-4(1H)-ones, was favoured.

Discovery of Quinazolin-4(3 H)-ones as NLRP3 Inflammasome Inhibitors: Computational Design, Metal-Free Synthesis, and in Vitro Biological Evaluation

NLRP3 inflammasome is an important therapeutic target for a number of human diseases. Herein, computationally designed series of quinazolin-4(3 H)-ones were synthesized using iodine-catalyzed coupling of arylalkynes (or styrenes) with O-aminobenzamides. The key event in this transformation involves the oxidative cleavage of the C-C triple/double bond and the release of formaldehyde. The reaction relies on the C-N bond formation along with the C-C bond cleavage under metal-free conditions. The nitro-substituted quinazolin-4(3 H)-one 2k inhibited NLRP3 inflammasome (IC₅₀ 5 μM) via the suppression of IL-1β release from ATP-stimulated J774A.1 cells.

Copper-catalyzed synthesis of 2,3-disubstituted quinazolin-4(3H)-ones from benzyl-substituted anthranilamides

An efficient, practical approach to the copper-catalyzed synthesis of 2,3-disubstituted quinazolin-4(3H)-one derivatives is described. The preparation involves treatment of benzyl amines with benzyl anthranilamides in the presence of Cu(OAc)2 and tetra-n-butylammonium bromide (TBAB).

Bismuth-Catalyzed Synthesis of 2-Substituted Quinazolinones

The bismuth-catalyzed oxidative condensation of aldehydes with 2-aminobenzamide under aerobic conditions is reported using ethanol as the solvent. Good to excellent isolated yields (68-95%) of the corresponding 2-substituted quinazolinones were obtained under mild reaction conditions with excellent functional group tolerance. The quinazolinones were further functionalized to afford N-allylated quinazolinones, 2-aminopyridine derivatives, and annulated polyheterocyclic compounds via transition-metal catalyzed reactions.

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.

Base-promoted ring opening of 3-chlorooxindoles for the construction of 2-aminoarylthioates and their transformation to quinazolin-4(3H)-ones

Cesium carbonate-promoted synthesis of diverse 2-aminoarylthioates via ring opening of 3-chlorooxindoles with thiols, and their synthetic applications is demonstrated.

Crystal structure of 3-benzyl-2-[(E)-2-(furan-2-yl)ethen-yl]-2,3-di-hydro-quinazolin-4(1H)-one and 3-benzyl-2-[(E)-2-(thio-phen-2-yl)ethen-yl]-2,3-di-hydro-quinazolin-4(1H)-one from synchrotron X-ray diffraction

The chiral title compounds, C21H18N2O2, (I), and C21H18N2OS, (II) - products of the three-component reaction between benzyl-amine, isatoic anhydride and furyl- or thienyl-acrolein - are isostructural and form isomorphous racemic crystals. The tetra-hydro-pyrimidine ring in (I) and (II) adopts a sofa conformation. The amino N atom has a trigonal-pyramidal geometry [sum of the bond angles is 347.0° for both (I) and (II)], whereas the amido N atom is flat [sum of the bond angles is 359.3° for both (I) and (II)]. The furyl- and thienylethenyl substituents in (I) and (II) are planar and the conformation about the bridging C=C bond is E. These bulky fragments occupy the axial position at the quaternary C atom of the tetra-hydro-pyrimidine ring, apparently, due to steric reasons. In the crystals, mol-ecules of (I) and (II) form hydrogen-bonded helicoidal chains propagating along [010] by strong inter-molecular N-H⋯O hydrogen bonds.

Crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes: a bio-nanoreactor with extremely high activity toward click-multi-component reactions

In the present study, we have designed a procedure for the synthesis of a bio-nanoreactor catalyst, crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes (CS NPs/MWCNT@Fe₃O₄), via an in situ ionotropic gelation method.

Efficient preparation of boehmite silica dopamine sulfamic acid as a novel nanostructured compound and its application as a catalyst in some organic reactions

Nano-boehmite was prepared in water at room temperature using commercially available materials and applied as supports for the preparation of a new catalyst.