Synthetic approaches, functionalization and therapeutic potential of quinazoline and quinazolinone skeletons: the advances continue

Visible-Light-Induced Domino Perfluoroalkylation/Cyclization to Access Perfluoroalkylated Quinazolinones by an EDA Complex

The electron donor-acceptor (EDA) complexes have been extensively studied, which formed an electronically excited state, obviating the need for an exogenous photocatalyst. Herein, we report a mild and efficient strategy for photoinduced radical domino perfluoroalkylation/cyclization using N,N,N',N'-tetramethylethane-1,2-diamine (TMEDA) as an electron donor. This protocol could be well expanded to access various polycyclic quinazolinones containing perfluoroalkyl groups, exhibiting photocatalyst-free, good functional group tolerance, and environmentally friendly features.

Metal-free synthesis of 1,1-dimethyl-2,2,2-trifluoroethyl substituted quinazolinones via tandem radical cyclization of quinazolin-4(3H)-ones with 3,3,3-trifluoro-2,2-dimethylpropanoic acid

A metal-free (NH4)2S2O8-mediated decarboxylative trifluoromethylation reaction of alkenes with 3,3,3-trifluoro-2,2-dimethylpropionic acid has been proposed. This method offers a novel route for the direct synthesis of a series of CMe2CF3-containing quinazolinones from basic chemical raw materials. The reaction mechanism was studied by a radical trapping test and DFT methods, verifying an oxidation-triggered cascade process promoted by the CMe2CF3 radicals. This strategy provides advantages such as high yield, wide substrate compatibility, and high atom economy.

Discovery of ZJCK-6-46: A Potent, Selective, and Orally Available Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1A Inhibitor for the Treatment of Alzheimer's Disease

Targeting dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) has been verified to regulate the progression of tau pathology as a promising treatment for Alzheimer's disease (AD), while the research progress on DYRK1A inhibitors seemed to be in a bottleneck period. In this work, we identified 32 (ZJCK-6-46) as the most potential DYRK1A inhibitor (IC50 = 0.68 nM) through rational design, systematic structural optimization, and comprehensive evaluation. Compound 32 exhibited acceptable in vitro absorption, distribution, metabolism, and excretion (ADME) properties and significantly reduced the expression of p-Tau Thr212 in Tau (P301L) 293T cells and SH-SY5Y cells. Moreover, compound 32 showed favorable bioavailability, blood-brain barrier (BBB) permeability, and the potential of ameliorating cognitive dysfunction by obviously reducing the expression of phosphorylated tau and neuronal loss in vivo, which was deserved as a valuable molecular tool to reveal the role of DYRK1A in the pathogenesis of AD and to further promote the development of anti-AD drugs.

Green light-mediated dual eosin Y/PdII-catalyzed C(sp2)-H arylation of N-H unprotected 2-arylquinazolinones

We report herein an eosin Y/Pd(II) dual catalytic approach for regio- and chemoselective C(sp2)-H monoarylation of N-H unprotected 2-phenyl quinazolinone derivatives under green light irradiation with no necessity for any base/additive/external oxidant. The free N-H moiety was post-modified for quinazolinone scaffold diversification and C-H annulation.

Rhodium(III)-Catalyzed Annulation Synthesis of Difluorinated Quinazolinone Derivatives Using an Amide Carbonyl as the Directing Group

The use of amide carbonyl groups of substrates as weakly coordinating directing groups has received a significant amount of attention. Recently, difluoromethylene alkynes have been successfully used in fluorination reactions, resulting in the preparation of various fluorine-containing compounds. This work describes a [4+2] annulation method for creating a range of fluorinated quinolino[2,1-b]quinazolinone derivatives. The derivatives are formed through Rh(III)-catalyzed cascade cyclization of 3-phenylquinazolinones and gem-difluoromethylene alkynes.

Access to N-Fused Quinazolinones by Radical-Promoted Cascade Annulations of Alkenyl N-Cyanamides with Aromatic Aldehydes

A cascade radical cyclization of alkenyl N-cyanamides with aromatic aldehydes has been achieved for an expeditious synthesis of keto-methylated dihydropyrrolo-quinazolinones. Benzoyl radicals, generated from aryl aldehydes in the presence of di-tert-butyl peroxide (DTBP), promoted the domino annulations leading to distinctive functionalized quinazolinones in good yields. In addition, the robustness of the present protocol is validated by employing heterocyclic and natural product-based aldehydes.

Recent Advances in Metal-Catalyzed Approaches for the Synthesis of Quinazoline Derivatives

Quinazolines are an important class of heterocyclic compounds that have proven their significance, especially in the field of organic synthesis and medicinal chemistry because of their wide range of biological and pharmacological properties. Thus, numerous synthetic methods have been developed for the synthesis of quinazolines and their derivatives. This review article briefly outlines the new synthetic methods for compounds containing the quinazoline scaffold employing transition metal-catalyzed reactions.

Visible-Light-Driven Decarboxylative Coupling of 2H-Indazoles with α-Keto Acids without Photocatalysts and Oxidants

An efficient synthesis of functionalized 3-acyl-2H-indazoles via visible-light-induced self-catalyzed energy transfer was developed. This method utilized a self-catalyzed energy transfer process between 2H-indazoles and α-keto acids, offering advantages like absence of photosensitizers, metal catalysts, and strong oxidants, broad substrate compatibility, and operational simplicity under mild conditions.

One-Pot Three-Component Reaction for the Synthesis of 3,4-Dihydroquinazolines and Quinazolin-4(3H)-ones

A highly efficient and straightforward one-pot synthesis of diversely substituted 3,4-dihydroquinazolines and quinazolin-4(3H)-ones has been achieved through a domino three-component assembly reaction of arenediazonium salts, nitriles, and bifunctional aniline derivatives. This new protocol involves three C-N bond formations through the initial formation of N-arylnitrilium intermediates from arenediazonium salts and nitriles, followed by the sequential nucleophilic addition and cyclization reactions with bifunctional anilines, leading to such N-heterocyclic compounds of biological and pharmacological importance. This method offers a simple, expedient, and robust approach with the use of amenable and easily accessible reactants/reagents under metal-free mild conditions, good functional group tolerance, and high efficiency. The synthetic applications were also demonstrated by derivatization of the products obtained from these processes and syntheses of a diverse range of valuable polycyclic N-heterocycles.

Photogenerated chlorine radicals activate C(sp3)-H bonds of alkylbenzenes to access quinazolinones

An Fe-catalyzed visible-light induced condensation of alkylbenzenes with anthranilamides has been developed. Upon irradiation, the trivalent iron complex could generate chlorine radicals, which successfully abstracted the hydrogen of benzylic C-H bonds to form benzyl radicals. And these benzyl radicals were converted into oxygenated products under air conditions, which subsequently reacted with anthranilamides for the synthesis of quinazolinones.

Critical view on antimicrobial, antibiofilm and cytotoxic activities of quinazolin-4(3H)-one derived schiff bases and their Cu(II) complexes

A series of nine 2,3-disubstituted-quinazolin-4(3H)-one derived Schiff bases and their three Cu(II) complexes was prepared and tested for their antimicrobial activities against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis (VRE). All the substances were tested in vitro against Mycobacterium tuberculosis H37Ra ATCC 25177, M. kansasii DSM 44162 and M. smegmatis ATCC 700084. While anti-enterococcal and antimycobacterial activities were insignificant, 3-[(E)-(2-hydroxy-5-nitrobenzylidene)amino]-2-(2-hydroxy-5-nitrophenyl)-2,3-dihydroquinazolin-4(1H)-one (SB3) and its Cu(II) complex (SB3-Cu) demonstrated bacteriostatic antistaphylococcal activity. In addition, both compounds, as well as the other two prepared complexes, showed antibiofilm activity, which resulted in a reduction of biofilm formation and eradication of mature S. aureus biofilm by 80% even at concentrations lower than the values of their minimum inhibitory concentrations. In addition, the compounds were tested for their cytotoxic effect on the human monocytic leukemia cell line THP-1. The antileukemic efficiency was improved by the preparation of Cu(II) complexes from the corresponding non-chelated Schiff base ligands.

Total Synthesis of Cyclotripeptidic Natural Products Anacine, Aurantiomide C, Polonimides A and C, and Verrucine F

The total synthesis of cyclotripeptidic natural products possessing a central piperazino[2,1-b]quinazolin-3,6-dione core is described through an original strategy involving the pivotal cyclocondensation of an electrophilic homoserine lactone intermediate. The alkylidene group was spontaneously installed by autoxidation during the cyclocondensation process, while the propionamide side chain was introduced through the nickel-catalyzed aminocarbonylation of a bromoethyl intermediate. This last reaction is unprecedented on such highly functionalized intermediates. Finally, we explored structural modifications and interconversions of the natural products. Overall, this work led to anacine, aurantiomide C, polonimides A and C, and verrucine F.

Regioselective quinazoline C2 modifications through the azide-tetrazole tautomeric equilibrium

2-Chloro-4-sulfonylquinazolines undergo functional group swap when treated with an azide nucleophile: 1) the azide replaces the sulfonyl group at the C4 position; 2) the intrinsic azide-tetrazole tautomeric equilibrium directs the nucleofugal sulfinate from the first step to replace chloride at the C2 position. This transformation is effective with quinazolines bearing electron-rich substituents. Therefore, the title transformations are demonstrated on the 6,7-dimethoxyquinazoline core, which is present in pharmaceutically active substances. The methodology application is showcased by transforming the obtained 4-azido-6,7-dimethoxy-2-sulfonylquinazolines into the α1-adrenoceptor blockers terazosin and prazosin by further C2-selective SNAr reaction and azide reduction.

Access to CF2COR-Containing Quinazolinones via Visible-Light-Induced Domino Difluoroalkylation/Cyclization of N-Cyanamide Alkenes

A green and highly efficient visible-light-induced radical cascade difluoroalkylation/cyclization reaction of N-cyanamide alkenes has been developed. A variety of CF2COR-containing quinazolinones have been obtained in high yields with cheap non-metallic 4CzIPN as the photocatalyst. This photocatalytic reaction provides rapid, facile, and practical access to valuable polycyclic quinazolinone, and it is amenable to the gram scale.

Skeletal Editing through Molecular Recombination of 2H-Indazoles to Azo-Linked-Quinazolinones

A new protocol by the combinatory use of two equivalent of indazoles starting material with one being the carbon source via its C3-reactivity and the other, the coupling partner has been developed for the selectfluor-mediated single atom skeletal editing of 2H-indazoles. The azo-linked-2,3-disubstituted quinazolin-4-one derivatives were obtained through a carbon atom insertion between the two nitrogens of the indazole ring and simultaneous oxidation at C3 position of both indazole moieties. Mechanistic investigations reveal that the amidic carbonyl oxygen of the product is derived from water and the reaction proceeds through in-situ generated N-centred indazolone radical intermediate.

Electrochemical-Induced C-N Bond Formation: A New Method to Synthesis (Z)-Quinazolinone Oximes Using Primary Amines and Quinazolin-4(3H)-one

A novel and highly selective electrochemical method for the synthesis of diverse quinazolinone oximes via direct electrooxidation of primary amines/C(sp2)-H functionalization of oximes has been developed. The reaction is conducted in an undivided cell under constant current conditions and is oxidant-free, open-air, and eco-friendly. Notably, the protocol shows good functional group tolerance, providing versatile quinazolinone oximes in good yields. Moreover, the mechanism is investigated through control experiments and cyclic voltammogram (CV) experiments.

Synthesis and molecular docking simulations of novel azepines based on quinazolinone moiety as prospective antimicrobial and antitumor hedgehog signaling inhibitors

A series of novel azepine derivatives based on quinazolinone moiety was synthesized through the reaction of quinazolinone chalcones (2a-d) either with 2-amino aniline in acidic medium to give diazepines (3a-d) or with 2-aminophenol to offer oxazepine (4a-d). The structure of the synthesized compounds was confirmed via melting points, elemental analyses, and different spectroscopic techniques. Moreover, these newly compounds mode of action was investigated in-silico using molecular docking against the outer membrane protein A (OMPA), exo-1,3-beta-glucanase for their antimicrobial activity, and against Smoothened (SMO), transcription factor glioma-associated homology (SUFU/GLI-1), the main proteins of Hedgehog signaling pathway to inspect their anticancer potential. Our results showed that, diazepine (3a) and oxazepine (4a) offered the highest binding energy against the target OMPA/ exo-1,3-beta-glucanase proteins and exhibited the potent antimicrobial activities against E. coli, P. aeruginosa, S. aureus, B. subtilis, C. Albicans and A. flavus. As well, diazepine (3a) and oxazepine (4a) achieved the best results among the other compounds, in their binding energy against the target SMO, SUFU/GLI-1 proteins. The in-vitro cytotoxic study was done for them on panel of cancer cell lines HCT-116, HepG2, and MCF-7 and normal cell line WI-38. Conclusively, it was revealed that molecular docking in-silico simulations and the in-vitro experiments were agreed. As a result, our findings elucidated that diazepine (3a) and oxazepine (4a), have the potential to be used as antimicrobial agents and as possible cancer treatment medications.

Visible-light photocatalyzed C-N bond activation of tertiary amines: a three-component approach to synthesize quinazolines

A metal-free three-component approach has been developed to prepare 2,4-disubstituted quinazolines from o-acylanilines, trialkylamines and ammonium chloride under visible-light using eosin Y as the photocatalyst. The notable features of this work include (i) the use of tertiary amines as an alkyl synthon and triethanolamine as a C2-OH synthon; (ii) good functional group tolerance with 52%-98% yields; (iii) proof of concept with o-amino benzaldehyde as a substrate to deliver 2-methyl quinazoline 3pa; and (iv) gram-scale synthesis of compounds 3ga, 3ja and 3ma. A reductive quenching mechanism was proposed based on the control studies and redox potential values.

Cyclizations of Alkenyl(Alkynyl)-Functionalized Quinazolinones and their Heteroanalogues: A Powerful Strategy for the Construction of Polyheterocyclic Structures

Quinazolin-4-one, its heteroanalogues, and derivatives represent an outstandingly important class of compounds in modern organic, medicinal, and pharmaceutical chemistry, as these molecular structures are noted for their wide synthetic and pharmacological potential. In the last years, ever-increasing research attention has been paid to quinazolinone derivatives bearing alkenyl and alkynyl substituents on the pyrimidinone nucleus. The original structural combination of synthetically powerful endocyclic amidine (or amidine-related) and exocyclic unsaturated moieties provides a driving force for cyclizations, which offer an efficient toolkit to construct a variety of fused pyrimidine systems with saturated N- and N,S-heterocycles. In this connection, the present review article is mainly aimed at systematic coverage of the progress in using alkenyl(alkynyl)quinazolinones and their heteroanalogues as convenient bifunctional substrates for regioselective annulation of small- and medium-sized heterocyclic nuclei. Much attention is paid to elucidating the structural and electronic effects of reagents on the regio- and stereoselectivity of the cyclizations as well as to clarifying the relevant reaction mechanisms.

Clean Synthetic Strategies to Biologically Active Molecules from Lignin: A Green Path to Drug Discovery

Deriving active pharmaceutical agents from renewable resources is crucial to increasing the economic feasibility of modern biorefineries and promises to alleviate critical supply-chain dependencies in pharma manufacturing. Our multidisciplinary approach combines research in lignin-first biorefining, sustainable catalysis, and alternative solvents with bioactivity screening, an in vivo efficacy study, and a structural-similarity search. The resulting sustainable path to novel anti-infective, anti-inflammatory, and anticancer molecules enabled the rapid identification of frontrunners for key therapeutic indications, including an anti-infective against the priority pathogen Streptococcus pneumoniae with efficacy in vivo and promising plasma and metabolic stability. Our catalytic methods provided straightforward access, inspired by the innate structural features of lignin, to synthetically challenging biologically active molecules with the core structure of dopamine, namely, tetrahydroisoquinolines, quinazolinones, 3-arylindoles and the natural product tetrahydropapaveroline. Our diverse array of atom-economic transformations produces only harmless side products and uses benign reaction media, such as tunable deep eutectic solvents for modulating reactivity in challenging cyclization steps.

Furan-Dihydroquinazolinone Based Fluorescent Nanoprobe for Selective Recognition of 4-Nitrophenol: A Spectofluorimetric Approach

Fluorescent organic nanoparticles (FONPs) have attracted much attention as a practicable and effective platform for detection applications. The present article describes the preparation of FONPs derived from the quinazolinone-based 2-(furan-2-yl)-2,3-dihydroquinazolin-4(1H)-one derivative FHDQ. Self-assembly of FHDQ in an aqueous medium resulted in the formation of FONPs through H-type aggregation and showed excellent fluorescence properties. The presence of other coexisting species solutions did not affect the selective fluorescence quenching observed with the addition of 4-nitrophenol (4-NP). The photophysical properties, i.e., UV-Vis absorbance, fluorescence emission, and lifetime measurements together with zeta particle sizer, support excited-state complex formation followed by a dynamic fluorescence quenching phenomenon in the emission of FDHQNPs. In the concentration range of 0 to 36 μg.[Formula: see text], the detection limit of this turn-off sensor FDHQNPs against 4-NP was determined to be 0.01611 μM. Finally, the practicability of the FDHQNPs for the analysis of 4-NP in environmental samples was demonstrated.

Novel fused imidazotriazines acting as promising top. II inhibitors and apoptotic inducers with greater selectivity against head and neck tumors: Design, synthesis, and biological assessments

Although the great effectiveness of doxorubicin (Dox) in the treatment of many types of tumors, it showed limited effectiveness against the head and neck squamous cell carcinoma (HNSCC) subtype which is attributed to its reported multiple drug resistance (MDR). In the current study, we considered the essential pharmacophoric features of Dox as an effective Top. II inhibitor and sought to develop a novel set of imidazo[1,2-a] [1,3,5]triazin-2-amines (2a-2p) as a suggested anticancer option that could intercalate the DNA base pairs. We evaluated the % inhibition of the newly synthesized compounds on thirteen cancer cell lines and the analysis of structure-activity relationships revealed that the human head and neck cancer cell line (HNO97) was the most sensitive to their growth inhibition effect. Then, the IC50 values were recorded against the most sensitive cancer cell lines (HNO97, MDA-MB-231, and HEPG2), and compared to the normal cell line OEC (human oral epithelial cells). Compounds 2f and 2g showed very strong activities against HNO97 with IC50 values of (4 ± 1 and 3 ± 1.5 μg/mL), respectively, compared to that of Dox (9 ± 1.6 μg/mL). Next, a quantitative determination of human DNA Top. II concentrations in the most sensitive cell line (HNO97) were recorded for the most active anticancer derivatives. Again, compound 2f showed a superior Top. II inhibition with 87.86% compared to that of Dox (86.44%), while compound 2g achieved an inhibition of 81.37% which was close to the effect of Dox. To further investigate their effects on cell cycle progression and apoptosis induction in HNO97 cells, both 2f and 2g were selected for analysis. Both candidates arrested cell cycle progression at both the S and G2-M phases, as well as increased the early and late apoptosis phase ratios. Besides, both 2f and 2g were subjected to protein expression analysis of apoptosis-related genes (p53, BAX, IL-6, and BCL2). Moreover, the antioxidant effect of 2f and 2g was evaluated by measuring GSH, MDA, and NO markers in HNO97 cells. Furthermore, molecular docking for the newly designed tricyclic derivatives against both the Top. II and DNA double helix was carried out.

Facile synthesis of triazolo/benzazolo[2,1-b]quinazolinone derivatives catalyzed by a new deep eutectic mixture based on glucose, pregabalin and urea

In this study, a novel natural deep eutectic solvent was prepared from glucose, pregabalin, and urea. The prepared solvent was identified using a variety of techniques, including Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and refractive index measurements (RI). The prepared deep eutectic solvent was then utilized for the one-pot synthesis of quinazolinone derivatives. The yields of the product obtained with and without the catalyst were determined, providing insights into the catalytic efficiency of the system. This protocol offers several advantages, including mild reaction conditions, easy reagent preparation, a green process, short reaction times (2-60 min), high yields (80-99%), and a straightforward procedure with the possibility of catalyst reusability.

Construction of benzoheterocycles by the reaction of α-arylglyoxylic acids and ortho-functionalized aniline under mild and minimal conditions

This work describes an environmentally friendly method for the synthesis of benzoxazinones, quinoxalinones and benzothiazoles by the reaction of α-arylglyoxylic acids and ortho-functionalized aniline. In this reaction, no other reagents are needed except for reactants and solvents. The reaction was carried out at a mild temperature of 50 °C with only water and/or carbon dioxide as the by-product. Therefore, the reaction has high practical atom economy. In addition, this strategy could be scaled up to the gram level, and the natural product Cephamandole A could be synthesized on a mass scale.

CuI-catalyzed synthesis of multisubstituted pyrido[1,2-a]pyrimidin-4-ones through tandem Ullmann-type C-N cross-coupling and intramolecular amidation reaction

Various multi-substituted pyrido[1,2-a]pyrimidin-4-ones were synthesized via a one-pot tandem CuI-catalyzed C-N bond formation/intramolecular amidation reaction at 130 °C in DMF. This protocol features simple operation, broad substrate scope, good functional group tolerance and gram scale preparation, thus allowing practical and modular synthesis of pyrido[1,2-a]pyrimidin-4-ones from readily available 2-halopyridine and (Z)-3-amino-3-arylacrylate ester in good to excellent yields.

Synthesis of fused quinazolinones via visible light induced cyclization of 2-aminobenzaldehydes with tetrahydroisoquinolines

This study reports a novel method for the synthesis of fused quinazolinones by visible-light-induced cyclization of 2-aminobenzaldehydes and tetrahydroisoquinolines. The reaction is easily carried out by irradiation with a blue LED in the presence of 9-fluorenone and air. A broad substrate scope with good tolerance of functionalities was observed under the optimized reaction conditions. Moreover, using 2-aminophenone as the substrate and under similar reaction conditions, the same product was obtained when a carbon was removed. The bio-active naturally occurring alkaloid rutaecarpine could be obtained by this strategy. The success of the reaction on the gram-scale and the further transformation of the substrate demonstrated the synthetic practicability of this reaction.

One-Pot Synthesis of Isoxazole-Fused Tricyclic Quinazoline Alkaloid Derivatives via Intramolecular Cycloaddition of Propargyl-Substituted Methyl Azaarenes under Metal-Free Conditions

A practical method was developed for the convenient synthesis of isoxazole-fused tricyclic quinazoline alkaloids. This procedure accesses diverse isoxazole-fused tricyclic quinazoline alkaloids and their derivatives via intramolecular cycloaddition of methyl azaarenes with tert-butyl nitrite (TBN). In this method, TBN acts as the radical initiator and the source of N-O. Moreover, this protocol forms new C-N, C-C, and C-O bonds via sequence nitration and annulation in a one-pot process with broad substrate scope and functionalization of natural products.

Divergent Protocol for the Synthesis of Isoquinolino[1,2-b]quinazolinone and Isoquinolino[2,1-a]quinazolinone Derivatives

The development of robust and step-economic strategies to access structurally diverse drug-like compound collections remains a challenge. A distinct structural option that constitutes the core scaffold of many biologically significant molecules is the quinazolinone ring system. Several members of this family of privileged substructures have gained attention due to their diverse biological activities. In this context, the development of an efficient strategy for their access is needed. Herein, we report a divergent metal-free operation to access a diverse collection of C6-substituted pyrrolo[4',3',2':4,5]isoquinolino[1,2-b]quinazolin-8(6H)-one and pyrrolo[4',3',2':4,5]isoquinolino[2,1-a]quinazolin-12(6H)-one architectures. The described cascade unites Friedel-Crafts and aza-Michael addition reactions. This operationally simple protocol enables a rapid access to these scaffolds and is compatible with a wide scope of starting materials. In addition, the cascade features a promising approach for the design of unique compound libraries for drug design and discovery programs.

Polyphosphoric Acid Esters Promoted Synthesis of Quinazolin-4(3H)-imines from 2-Aminobenzonitrile

A novel method for the synthesis of quinazolin-4(3H)-imines (QIs) by trimethylsilyl polyphosphate (PPSE) promoted reaction of 2-aminobenzonitrile with secondary amides is reported. The reaction is general and allows for the synthesis of N3-aryl and N3-alkyl QIs with variable 2-substituents affording high yields. The procedure was extended to derivatives bearing additional functional groups. The method is operationally simple, involves easily available starting materials and a mild dehydrating agent, with wide functional group tolerance. The reaction procedure proved to be suitable for scaling-up. A possible reaction path via an intermediate nitrilium ion is proposed on the basis of literature data and experimental observations.

Design, synthesis, and cytotoxic evaluation of quinazoline derivatives bearing triazole-acetamides

A novel series of quinazoline-based agents bearing triazole-acetamides 8a-l were designed and synthesized. All the obtained compounds were tested for in vitro cytotoxic activities against three human cancer cell lines named HCT-116, MCF-7, and HepG2, as well as a normal cell line WRL-68 after 48 and 72 h. The results implied that quinazoline-oxymethyltriazole compounds exhibited moderate to good anticancer potential. The most potent derivative against HCT-116 was 8a (X = 4-OCH₃ and R = H) with IC₅₀ values of 10.72 and 5.33 μM after 48 and 72 h compared with doxorubicin with IC₅₀ values of 1.66 and 1.21 μM, respectively. The same trend was seen in the HepG2 cancerous cell line in which 8a recorded the best results with IC₅₀ values of 17.48 and 7.94 after 48 and 72 h, respectively. The cytotoxic analysis against MCF-7 showed that 8f with IC₅₀ = 21.29 μM (48 h) exhibited the best activity, while compounds 8k (IC₅₀ = 11.32 μM) and 8a (IC₅₀ = 12.96 μM), known as the most effective cytotoxic agents after 72 h. Doxorubicin as positive control exhibited IC₅₀ values of 1.15 and 0.82 μM after 48 and 72 h, respectively. Noteworthy, all derivatives showed limited toxicity against the normal cell line. Moreover, docking studies were also presented to understand the interactions between these novel derivatives and possible targets.

Room temperature ligand-free Cu2O-H2O2 catalyzed tandem oxidative synthesis of quinazoline-4(3H)-one and quinazoline derivatives

An efficient and simple copper catalytic system has been developed for the synthesis of medicinally important 2-substituted quinazoline-4(3H)-ones from 2-aminobenzonitrile and benzyl alcohol derivatives and additionally 2-substituted quinazolines from 2-aminobenzylamine and benzaldehyde derivatives. Mild oxidant H₂O₂ was utilized, providing excellent product yields. The molecular structure of one of the compounds was substantiated through SC-XRD. The versatility of the protocol was demonstrated through gram-scale syntheses.

Tandem C-C/C-N Bond Formation via Rh(III)-Catalyzed α-Fluoroalkenylation and Sequential Annulation of 2-Arylquinazolinones and gem-Difluorostyrenes

An efficient method of Rh(III)-catalyzed coupling reaction between 2-arylquinazolinones and gem-difluorostyrenes has been developed. In this work, two diverse structures of monofluoroalkenes and isoindolo[1,2-b]quinazolin-10(12H)-one derivatives were respectively synthesized by controlling the amount of additives (Ca(OH)₂ and AgNTf₂) to achieve controlled stepwise breaking of the C-F bonds of gem-difluorostyrenes. This reaction has the characteristics of a wide range of substrates and good functional group tolerance. Meanwhile, several control experiments were conducted and a plausible mechanism was proposed.

An Insight on the Prospect of Quinazoline and Quinazolinone Derivatives as Anti-tubercular Agents

Multiple potential drugs have been developed based on the heterocyclic molecules for the treatment of different symptoms. Among the existing heterocyclic molecules, quinazoline and quinazolinone derivatives have been found to exhibit extensive pharmacological and biological characteristics. One significant property of these molecules is their potency as anti-tubercular agents. Thus, both quinazoline and quinazolinone derivatives are modified using different functional groups as substituents for investigating their anti-tubercular activities. We present a summary of the reported anti-tubercular drugs, designed using quinazoline and quinazolinone derivatives, in this review.

Pyridyl Glycosyl Triazole/CuI-Mediated Domino/Tandem Synthesis of Quinazolinones

The glycosyl 1,2,3-triazoles are expediently accessible from readily available sugar-derived glycosyl azide by utilizing modular CuAAC "Click Chemistry", and the resulting glycohybrid skeleton possesses efficient metal-coordinating centers that support a wide range of metal-mediated efficient catalysis in various imperative organic transformations. Here, we designed and developed pyridyl glycosyl triazoles by employing the CuAAC reaction of d-glucose-derived glycosyl azides and alkynyl pyridines. These pyridyl glycosyl triazoles with Cu(I) salt were explored as an efficient catalyst to successfully assemble 2-amino-3-substituted and 3-substituted quinazolinones by the domino/tandem cross-coupling reaction of various N-substituted o-halobenzamides with cyanamide and formamide, respectively. The devised protocol has some notable features, including biocompatibility, low cost, easily accessible starting materials for the glycosyl ligands, high yield, broad spectrum, low catalytic loading, and mild reaction conditions.

Dehydrogenative Synthesis of Quinolines and Quinazolines via Ligand-Free Cobalt-Catalyzed Cyclization of 2-Aminoaryl Alcohols with Ketones or Nitriles

We present a convenient and efficient protocol to synthesize quinolines and quinazolines in one pot under mild conditions. A variety of substituted quinolines were synthesized in good to excellent yields (up to 97% yield) from the dehydrogenative cyclizations of 2-aminoaryl alcohols and ketones catalyzed by readily available Co(OAc)₂·4H₂O. This cobalt catalytic system also showed high activity in the reactions of 2-aminobenzyl alcohols with nitriles, affording various quinazoline derivatives (up to 95% yield). The present protocol offers an environmentally benign approach for the synthesis of N-heterocycles by employing an earth-abundant cobalt salt under ligand-free conditions.

Recent advances and prospects in the organocatalytic synthesis of quinazolinones

Quinazolinone, a bicyclic compound, comprises a pyrimidine ring fused at 4´ and 8´ positions with a benzene ring and constitutes a substantial class of nitrogen-containing heterocyclic compounds on account of their frequent existence in the key fragments of many natural alkaloids and pharmaceutically active components. Consequently, tremendous efforts have been subjected to the elegant construction of these compounds and have recently received immense interest in synthetic and medicinal chemistry. The domain of synthetic organic chemistry has grown significantly over the past few decades for the construction of highly functionalized therapeutically potential complex molecular structures with the aid of small organic molecules by replacing transition-metal catalysis. The rapid access to this heterocycle by means of organocatalytic strategy has provided new alternatives from the viewpoint of synthetic and green chemistry. In this review article, we have demonstrated a clear presentation of the recent organocatalytic synthesis of quinazolinones of potential therapeutic interests and covered the literature from 2015 to date. In addition to these, a clear presentation and understanding of the mechanistic aspects, features, and limitations of the developed reaction methodologies have been highlighted.

Facile Access to 2-Selenoxo-1,2,3,4-tetrahydro-4-quinazolinone Scaffolds and Corresponding Diselenides via Cyclization between Methyl Anthranilate and Isoselenocyanates: Synthesis and Structural Features

A practical method for the synthesis of 2-selenoxo-1,2,3,4-tetrahydro-4-quinazolinone was reported. The latter compounds were found to undergo facile oxidation with H2O2 into corresponding diselenides. Novel organoselenium derivatives were characterized by the 1H, 77Se, and 13C NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, IR, elemental analyses (C, H, N), and X-ray diffraction analysis for several of them. Novel heterocycles exhibited multiple remarkable chalcogen bonding (ChB) interactions in the solid state, which were studied theoretically.

Novel Quinazolinone–Isoxazoline Hybrids: Synthesis, Spectroscopic Characterization, and DFT Mechanistic Study

Quinazolinone and isoxazoline systems have attracted much attention due to their interesting pharmacological properties. The association of these two pharmacophores in a single hybrid structure can boost the biological activity or bring a new one. Inspired by this new paradigm, in the present work we report the synthesis and spectroscopic characterization of new quinazolinone–isoxazoline hybrids. The target compounds were obtained via 1,3-dipolar cycloaddition reactions of arylnitriloxides and N-allylquinazolinone. The synthesized compounds were characterized using spectroscopic techniques such as IR, 1D NMR (1H and 13C), 2D NMR (COSY and HSQC), and high-resolution mass spectrometry (HRMS). The spectral data show that this reaction leads only to the 3,5-disubstituted isoxazoline regioisomer, and that the observed regiochemistry is not affected by the nature of the substituents in the phenyl ring of the dipole. In addition, a theoretical study was performed using density functional theory (DFT) to support the experimental results in regard to the regiochemistry of the studied reactions. The computational mechanistic study was in good agreement with the experimental data.

Synthesis, molecular docking, and cytotoxicity of quinazolinone and dihydroquinazolinone derivatives as cytotoxic agents

Background

Cancer is the most cause of morbidity and mortality, and a major public health problem worldwide. In this context, two series of quinazolinone 5a–e and dihydroquinazolinone 10a–f compounds were designed, synthesized as cytotoxic agents.

Methodology

All derivatives (5a–e and 10a–f) were synthesized via straightforward pathways and elucidated by FTIR, ¹H-NMR, CHNS elemental analysis, as well as the melting point. All the compounds were evaluated for their in vitro cytotoxicity effects using the MTT assay against two human cancer cell lines (MCF-7 and HCT-116) using doxorubicin as the standard drug. The test derivatives were additionally docked into the PARP10 active site using Gold software.

Results and discussion

Most of the synthesized compounds, especially 5a and 10f were found to be highly potent against both cell lines. Synthesized compounds demonstrated IC₅₀ in the range of 4.87–205.9 μM against HCT-116 cell line and 14.70–98.45 μM against MCF-7 cell line compared with doxorubicin with IC₅₀ values of 1.20 and 1.08 μM after 72 h, respectively, indicated the plausible activities of the synthesized compounds.

Conclusion

The compounds quinazolinone 5a–e and dihydroquinazolinone 10a–f showed potential activity against cancer cell lines which can lead to rational drug designing of the cytotoxic agents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13065-022-00825-x.

Synthesis of quinazolinone derivatives containing an acyl hydrazone skeleton as potent anti-urease agents enzyme kinetic studies and anti-oxidant properties

This paper covers the synthesis, in vitro urease inhibition, enzyme kinetic parameters, and anti-oxidant studies of a novel series of quinazolinone derivatives containing an acyl hydrazone skeleton. Compounds 3a, 3b, 5a, and 5b, having IC50 values ranging from 1.86 ± 0.07 to 6.38 ± 0.11 µg mL−1, show greater inhibitory activity than the standard inhibitor, thiourea. Among the products, (2-[2-(3-methoxybenzyl)-4-oxoquinazolin-3(4 H)-yl]acetohydrazide) proves to be the most potent, exhibiting enzyme inhibition activity with an IC50 value of 1.86 ± 0.07 µg mL−1. Kinetic studies involving the Lineweaver–Burk plots reveal that the inhibition mechanism of the most active compounds (3a, 3b, 5a, and 5b) on urease activity are found to be in competitive mode. Also, the anti-oxidant activity and radical-scavenging properties of the synthesized compounds are evaluated using cupric reducing anti-oxidant activity, ferric reducing anti-oxidant capacity, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), and 2,2-diphenyl-1-picrylhydrazyl assays. Compounds 3a, b and 5a, b have good anti-oxidant properties and radical-scavenging activity at various final concentrations.

CF3SO2Na-Mediated Visible-Light-Induced Cross-Dehydrogenative Coupling of Heteroarenes with Aliphatic C(sp3)-H Bonds

Minisci-type reaction is one of the important means to construct C(sp³)-H functionalization of heteroarenes. According to traditional methods, stoichiometric amounts of precious transition metal catalysts and chemical oxidants were required at high temperatures. Here, a green and gentle novel Minisci-type method was developed via visible-light-induced cross-dehydrogenative coupling of heteroarenes with aliphatic C(sp³)-H bonds under oxidant-free and transition-metal-catalyst-free conditions. Only the catalytic equivalent of CF₃SO₂Na and room temperature were required to maintain an efficient reaction.

The antibacterial activity of quinazoline and quinazolinone hybrids

Bacterial infections cause substantial morbidity and mortality across the world and pose serious threats to humankind. Drug resistance, especially multidrug resistance resulting from different defensive mechanisms in bacteria, is the leading cause of failure the chemotherapy, making it an urgent need to develop more effective antibacterials. Quinazoline and quinazolinone frameworks have received considerable attention due to their diversified therapeutic potential. In particular, quinazoline/quinazolinone hybrids could exert antibacterial activity through various mechanisms and are useful scaffolds for the discovery of novel antibacterials. This review principally emphases on the antibacterial potential, structure-activity relationships (SARs), and mechanism of action of quinazoline and quinazolinone hybrids, covering articles published between 2017 and 2021.