Novel and Efficient One-Pot Tandem Synthesis of 2-Styryl-Substituted 4(3H)-Quinazolinones

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.

Synthesis, antimalarial, antileishmanial evaluation, and molecular docking study of some 3-aryl-2-styryl substituted-4(3H)-quinazolinone derivatives

Quinazolinones are a diverse group of nitrogen-containing heterocyclic compounds with promising antimalarial and antileishmanial activities. Herein, some 3-aryl-2-styryl substituted-4(3H)-quinazolinones were synthesized via cyclization, condensation, and hydrolysis reactions. ¹H NMR, FTIR and elemental microanalysis was used to verify the structures of the synthesized compounds. The in vivo antimalarial and in vitro antileishmanial activities of the target compounds were investigated using mice infected with Plasmodium berghi ANKA and Leishmania donovani strain, respectively. Among the test compounds, 8 and 10 showed better antimalarial activities with percent suppression of 70.01 and 74.18, respectively. In addition, (E)-2-(4-nitrostyryl)-3-phenylquinazolin-4(3H)-one (6) showed promising antileishmanial activity (IC₅₀ = 0.0212 µg/mL). It is two and 150 times more active than the standard drugs amphotericin B deoxycholate (IC₅₀ = 0.0460 µg/mL) and miltefosine (IC ₅₀ = 3.1911 µg/mL), respectively. Its superior in vitro antileishmanial activity was supported by a molecular docking study conducted in the active site of Lm-PTR1. Overall, the synthesized 3-aryl-2-styryl substituted-4(3H)-quinazolinones showed promising antileishmanial and antimalarial activities and are desirable scaffolds for the synthesis of different antileishmanial and antimalarial agents.

A novel powerful Choline Chloride – Thiourea /Sulfuric Acid, efficient and recyclable catalyst via microwave‐assisted for the synthesis of Quinazolin- 4(3H)–one derivatives as Antibacterial Agents in green media

Background:

Choline Chloride - Thiourea / Sulfuric Acid is a powerful and efficient green catalyst used for one-pot synthesis of quinazoline-4 (3H) -one derivatives via a reaction between various amines, acetic anhydride, and anthranilic acid under microwave irradiation and solvent-free conditions (4a-q). Microwave irradiation, which is a faster, more cost-effective, less energy-intensive, and more efficient method than conventional heating, has been used to synthesize some quinazolinone derivatives.

Introduction:

For the past ten years, one of the major subjects in synthetic organic chemistry has been green synthesis, which has used efficient and environmentally friendly methods to synthesize biological compounds. The use of catalysts has significant advantages, including ease of preparation and separation, chemical and thermal stability, and environmental friendliness due to features such as reusability, low cost, and efficient, easy workup techniques. Therefore, the mechanism is performed by a non-toxic organic catalyst that uses the least energy and chemical reactants in accordance with the principles of green chemistry and least waste.

Methods:

One-pot and sequential addition methods have been used to synthesize quinazolinone derivatives. In the sequential addition method, the reaction was started by adding acetic anhydride and anthranilic acid to the reaction vessel under microwave irradiation and continued by adding choline chloride thiourea / sulfuric acid as efficient recyclable green catalysts and the desired amine. In vitro, the well diffusion method against different pathogenic strains was used to evaluate the antimicrobial activity of quinazoline-4 (3H) -one derivatives. Pathogenic strains used were Candida albicans ATCC 10231 (yeast), Aspergillus niger ATCC 16404 (fungus), Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 (bacteria) and ATCC 6538, and Staphylococcus aureus S. epidermidis ATCC 12228. Pyrimidine-containing compounds in which the 3-hydroxyl, 2,5-Dimethoxy, 4-bromo, 4 ‐ Methoxy, and 4 ‐ chloro groups are attached to the phenyl ring of pyrimidine exhibit antimicrobial properties.

Results:

In a short reaction time, a variety of biologically active quinazolinone derivatives were synthesized with a high efficiency. According to the results, it was found that with aliphatic amines, the reaction time was shorter and the reaction efficiency was higher. Products synthesized from aromatic amines had more antibacterial properties.

Conclusion:

In this work, a variety of 2-methyl-quinazoline-4 (3H) -one derivatives (4a–q) were synthesized as potent antibacterial agents under microwave irradiation and solvent-free conditions in the presence of ChCl-thiourea / H2SO4 as an efficient, eco-friendly, and recyclable catalyst.

Switchable and efficient conversion of 2-amido-aryl oxazolines to quinazolin-4(3H)-ones and N-(2-chloroethyl)benzamides

Switchable chemoselective conversion of 2-amido-aryl oxazolines to quinazolin-4(3H)-ones or N-(2-chloroethyl)benzamides is achieved.

Applications of alkyl orthoesters as valuable substrates in organic transformations, focusing on reaction media

In this review we focus on applications of alkyl orthoesters as valuable and efficient substrates to perform various classes of two-component and multi-component organic reactions. The article has classified them according to two aspects, which are: (i) a focus on the reaction medium (solvent-free conditions, aqueous media, and organic solvents); and (ii) an examination of product structures. Reaction accomplishment under solvent-free conditions is an eco-friendly process with the absence of volatile toxic solvents, which puts it in line with green chemistry goals. Water is an interesting choice in organic transformations due to its inexpensiveness and safety. The authors hope their assessment will help chemists to attain new approaches for utilizing alkyl orthoesters in various organic synthetic methods. The review covers the corresponding literature up to the beginning of 2020.

In this review we focus on applications of alkyl orthoesters as valuable and efficient substrates to perform various classes of two-component and multi-component organic reactions.

Guanylation/cyclisation of amino acid esters using an imidazolin-2-iminato titanium initiator

Catalytic hydroamination of amino acid esters with carbodiimides and isocyanates to furnish corresponding quinazolinone and urea derivatives using two Ti^IV complexes under mild conditions is reported.

Copper-Catalyzed Synthesis of 2-Arylquinazolinones from 2-Arylindoles with Amines or Ammoniums

A novel copper-catalyzed synthesis of quinazolinones from easily available 2-arylindoles and amines or ammoniums has been developed, which provided various quinazolinones in up to 99% yields for 43 examples. This strategy features tolerance of a wide range of functional groups, easily available starting materials, simple operation, mild reaction conditions, and environmental friendliness.

Efficient and Practical One-Pot Route to Synthesise Quinazolin4(3H)-Ones Using Trifluoromethanesulfonic Anhydride and 2-Chloropyridine

An effective, novel and rapid one-pot three-component route to quinazolin-4(3H)-ones from commercially available starting materials is described. Isatoic anhydride reacts with acyl chlorides and different amines using a combination of trifluoromethanesulfonic anhydride (Tf2O) and 2-chloropyridine (2-ClPy) to produce the corresponding quinazolinone derivatives in good to excellent yields.

Convenient synthesis of 2,3-disubstituted quinazolin-4(3H)-ones and 2-styryl-3-substituted quinazolin-4(3H)-ones: applications towards the synthesis of drugs

Simple, convenient, and green synthetic protocols have been developed for the one pot synthesis of 2,3-disubstituted quinazolin-4(3H)-ones and 2-styryl-3-substituted quinazolin-4(3H)-ones under catalyst and solvent free conditions.

One-Pot Tandem Approach for the Synthesis of Quinazolinones from ortho-Aminobenzamides, Benzyl Halides and Benzyl Alcohols

A one-pot tandem procedure is described for the synthesis of quinazolinones from benzyl halides or benzyl alcohols and ortho-aminobenzamides leading to the production of quinazolinones with high yields under mild conditions in DMSO without requiring an additional oxidant. According to the current method benzyl chlorides, benzyl bromides and benzyl alcohols bearing a range of substituents are suitable substrates.

Facile method for the combinatorial synthesis of 2,2-disubstituted quinazolin-4(1H)-one derivatives catalyzed by iodine in ionic liquids

A mild and facile method for the combinatorial synthesis of quinazolin-4-(1H)-one derivatives, containing simple 2,2-disubstituted quinazolin-4-(1H)-ones, spirocyclic quinazolin-4-(1H)-ones, spiro-heterocyclic quinazolin-4-(1H)-ones, and dispirocyclic quinazolin-4-(1H)-ones, is described, which results in high yields by using ionic liquids as green media. The method involves the reaction of 2-aminobenzamides with various ketones catalyzed by iodine and provides new quinazolin-4-(1H)-one library for biomedical screening.