Eco‐friendly and Efficient Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones

A simple and facile method for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones through the direct cyclocondensation of one‐pot three‐component cyclocondensation of isatoic anhydride, ammonium acetate (or primary amines) and aldehydes; and anthranilamide and aldehydes using silica supported ferric chloride (SiO₂‐FeCl₃) as catalyst under solvent‐free conditions is described.     

An efficient synthesis of 2,3‐dihydroquinazolin‐4(1H)‐one derivatives under catalyst‐free and solvent‐free conditions

A simple, efficient and convenient one‐pot synthesis of 2,3‐dihydroquinazolin‐4(1H)‐one derivatives under solvent‐free and catalyst‐free conditions by the reaction of aromatic aldehydes, isatoic anhydride, and ammonium acetate was reported. The advantages of this protocol include short reaction time, mild reaction conditions, easy work‐up, high yields, and environmental friendliness. J. Heterocyclic Chem., (2011).     

A three‐component process for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐one derivatives using nanosized nickel aluminate spinel crystals as highly efficient catalysts

NiAl₂O₄ spinel nanocrystals were synthesized as mesoporous catalysts and were fully characterized using Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction patterns (XRD), scanning electron microscopy (SEM), and Energy‐dispersive X‐ray spectroscopy (EDS). These nanocrystals catalyzed the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐one derivatives via a one‐pot, three‐component condensation reaction of aromatic aldehydes, isatoic anhydride, and ammonium acetate or primary aromatic amine under microwave irradiation. By far, the most obvious advantages of the offered process are efficiency and recyclability of the catalyst as well as a significantly shorter reaction time.     

CuBr/Et3N‐Promoted Reactions of 2‐Aminobenzamides and Isothiocyanates: Efficient Synthesis of Novel Quinazolin‐4(3H)‐ones

A series of novel quinazolin‐4(3H)‐one derivatives were efficiently synthesized starting from isatoic anhydride. First, reaction of isatoic anhydride and amines in H₂O at room temperature afforded 2‐aminobenzamides. Then, CuBr/Et₃N promoted reaction of 2‐aminobenzamides and different aryl isothiocyanates in DMF at 80° afforded the title compounds in good yield.     

One‐pot synthesis of 2,3‐disubstituted‐2,3‐dihydroquinazolin‐4(1H)‐ones using [Hmim][NO3]: An eco‐friendly protocol

An efficient method for the synthesis of a series of 2,3‐disubstituted‐2,3‐dihydroquinazolin‐4(1H)‐ones is described via one‐pot condensation reaction of isatoic anhydride, aryl aldehydes, and primary amines using a Brønsted acidic ionic liquid, [Hmim][NO₃], as a catalyst and medium. The present protocol enjoys convenient reaction and simple work‐up, greenness, short reaction times, and reusable catalyst as well as mild reaction conditions. J. Heterocyclic Chem., (2011).     

Ionic Liquid Promoted Eco-friendly and Efficient Synthesis of 2,3-Dihydroquinazolin-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

Summary. 2,3-Dihydroquinazolin-4(1H)-ones were efficiently synthesised by the reaction of isatoic anhydride, a primary amine or ammonium acetate, and different aromatic aldehydes in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF₄) without using any acidic catalyst. Also a bis-derivative of the title compound as a polyheterocyclic system was synthesised successfully in high yield.     

One‐pot Syntheses of Some New 2,4(1H,3H)‐quinazolinedione Derivatives in the Absence of Catalyst

A facile, rapid and one‐pot procedure for the synthesis of some new 2,4(1H ,3H )‐quinazolinediones is described. The method involves the one‐pot condensation of isatoic anhydride, primary amine and carbonyl diimidazole (CDI) in the absence of organic or inorganic catalyst. It affords the corresponding product in high yield.     

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

An environmentally benign magnetic silica‐based nanocomposite (Fe₃O₄/SBA‐15) as a heterogeneous nanocatalyst was prepared and characterized using Fourier transform infrared and ultraviolet–visible diffuse reflectance spectroscopies, scanning electron microscopy, X‐ray diffraction, vibrating sample magnetometry and Brunauer–Emmett–Teller multilayer nitrogen adsorption. Its catalytic activity was investigated for the one‐pot multicomponent synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones starting from isatoic anhydride, ammonium acetate and various aldehydes under mild reaction conditions and easy work‐up procedure in refluxing ethanol with good yields. The nanocatalyst can be recovered easily and reused several times without significant loss of catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

Unexpected Spiroproducts from the Reaction of N‐Benzoylglycine with Ortho‐Formylbenzoic Acids −3,5′‐Dioxo‐2′‐Phenyl‐1,3‐Dihydrospiro[Indene‐2,4′‐[1,3]Oxazol]‐1‐yl Acetates: Establishments of Their Structure

This paper describes a method of preparation of new 3,5′‐dioxo‐2′‐phenyl‐1,3‐dihydrospiro[indene‐2,4′‐[1,3]oxazol]‐1‐yl acetate and its 5‐chloro‐ and bromoderivatives as products of interaction of N‐benzoylglycine (hippuric acid) with corresponding ortho‐formylbenzoic acids. The reaction carried out in acetic anhydride media in the presence of piperidine as catalyst. The novel spirocompounds were purified by column chromatography from multicomponent reaction mixtures. The composition of the spiro‐products was confirmed by C, H, N element analysis. The structure was established by IR, MS, ¹H‐ and ¹³C‐NMR analysis including COSY ¹H‐¹³C experiments.     

An Environmental Friendly Approach for the Synthesis of Spiro[indoline‐3′,2‐quinazoline]2′,4(3H)‐dione Using 1‐Methylimidazolium Hydrogen Sulfate,as Reusable Catalyst

A facile and environmentally benign procedure for the synthesis of 3‐aryl‐1H‐spiro[indoline‐3′,2‐quin‐azoline]2′,4(3H)‐dione from isatoic anhydride, aromatic amines and isatin derivatives in Brønsted acidic ionic liquid, 1‐methylimidazolium hydrogen sulfate, was reported. The ability to reuse the ionic liquid, the high yield, short reaction time and ease of purification are the important features of this process.     

An Efficient One‐Pot Synthesis of 7,7‐Dimethyl‐2‐(2‐oxo‐2H‐chromen‐3‐yl)‐4‐aryl‐7,8‐dihydroquinolin‐5(6H)‐one Derivatives Using Chitosan–SO3H as Biodegradable Organocatalyst

Chitosan sulfonic acid (CS–SO₃H), a biodegradable green catalyst, was found to be an impressive system for one‐pot four‐component reaction of different aromatic aldehydes, 3‐acetylcoumarin, dimedone, and ammonium acetate leading to 7,7‐dimethyl‐2‐(2‐oxo‐2H‐chromen‐3‐yl)‐4‐aryl‐7,8‐dihydroquinolin‐5(6H)‐one under solvent‐free condition. This methodology produces diverse superiorities such as operational simplicity, short reaction time, and high yield. Further, the catalyst can be reused for four times without any noticeable decrease in the catalytic activity.     

Fe3O4@L‐arginine magnetic nanoparticles: A novel and magnetically retrievable catalyst for the synthesis of 1′3‐diaryl‐2N‐azaphenalene

The catalytic activity of l ‐arginine‐coated nano‐Fe₃O₄ particles (Fe₃O₄@l ‐arginine) proves they are a novel magnetic catalyst without the use of heat and reflux for the synthesis of 1,3‐diaryl‐2‐N‐azaphenalene derivatives and n‐acyl‐1,3‐diaryl‐2‐N‐azaphenylene derivatives in a one‐pot pseudo‐five‐component condensation reaction of compounds of 2,7‐naphthalene diol, aldehydes, and ammonia derivatives (ammonium acetate or ammonium hydrogen phosphate) and solvent (water and alcohol) with high yield and short reaction times, economical, and simple workup. The structure and magnetic properties of the obtained nanoparticles were characterized via Fourier transform infrared spectroscopy (IR) and field emission scanning electron microscopy (FE‐SEM). The results demonstrated that the average size of the synthesized magnetite nanoparticles is about 21 nm. In addition, the heterogeneous catalyst can be easily recovered magnetically and can be reused for further runs without significant loss of its catalytic activity.     

Synthesis of Novel Isoindolo[2,1‐a]quinazolinedione Derivatives Containing a 1,2,3‐Triazole Ring System

A synthesis of isoindolo[2,1‐a]quinazolinedione derivatives, coupled with a 1,2,3‐triazole ring system, via the reaction of isatoic anhydride, HC?CCH₂NH₂, and 2‐formylbenzoic acid is described, which led to the formation of the isoindolo[2,1‐a]quinazoline‐5,11‐dione scaffold having a C?C bond that participated in a click reaction with various organic azides.     

Synthesis of Novel 6‐Mercapto‐12‐phenethyl‐quinazolino[3,4‐a]quinazolinones

Novel 6‐mercapto‐12‐phenethyl‐quinazolino[3,4‐a]quinazolinone derivatives were synthesized through a user‐friendly five‐step reaction starting from isatoic anhydride. All products were characterized by IR, ¹H‐NMR, ¹³C‐NMR spectroscopy, and chemical analysis. All of them were evaluated for their in vitro cytotoxic activity against two cell lines namely MOLT‐4 (human lymphoblastic leukemia) and MCF‐7 (human breast adenocarcinoma).     

Ionic Liquid Promoted Eco-friendly and Efficient Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

2,3-Dihydroquinazolin-4(1H)-ones were efficiently synthesised by the reaction of isatoic anhydride, a primary amine or ammonium acetate, and different aromatic aldehydes in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF₄) without using any acidic catalyst. Also a bis-derivative of the title compound as a polyheterocyclic system was synthesised successfully in high yield.     

Inclusion complex of Isatoic anhydride with β-cyclodextrin and supramolecular one-pot synthesis of 2, 3-dihydroquinazolin-4(1H)-ones in aqueous media

The inclusion complex of isatoic anhydride with β-cyclodextrin was formed as a result of intermolecular interaction between isatoic anhydride with β-CD. The inclusion complex was confirmed by IR spectroscopy, X-ray diffraction and DSC studies. From application of complex, herein we have described a simple and efficient protocol for synthesis of 2, 3-dihydroquinazoline-4(1H)-one derivatives by one pot condensation of isatoic anhydride, ammonium acetate or amine and aldehyde using β-CD as a supramolecular catalyst in aqueous media.     

Efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by titanium silicon oxide nanopowder in aqueous media

An efficient synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives is accomplished in aqueous media by a three-component reaction of isatoic anhydride, primary amines or ammonium acetate, and aldehydes catalyzed by titanium silicon oxide nanopowder. A variety of 2,3-dihydroquinazolin-4(1H)-one derivatives were synthesized using this methodology in good to excellent yields. The catalyst was recovered and recycled up to four times without significant loss in the catalytic activity.     

(3‐Oxo‐[1,2,4]triazolidin‐1‐yl)bis (butane‐1‐sulfonic acid) functionalized magnetic γ‐Fe2O3 nanoparticles: A novel and heterogeneous nanocatalyst for one‐pot and efficient four‐component synthesis of novel spiro[indeno[1,2‐b]quinoxaline derivatives

The efficient synthesis of novel spiro[indeno[1,2‐b]quinoxaline derivatives via the four‐component condensation of amines, ninhydrin, isatoic anhydride, and о‐phenylenediamine derivatives catalyzed by ( 3‐oxo‐[1,2,4]triazolidin‐1‐yl)bis (butane‐1‐sulfonic acid) supported on γ‐Fe₂O₃ as novel heterogenous magnetic nanocatalyst was described. The novel nanocatalyst was characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), vibrating sample magnetometry (VSM), Field Emission Scanning Electron Microscopy (FE‐SEM), and thermal analysis (TGA‐DTG). The nanoparticles covered by (3‐oxo‐[1,2,4]triazolidin‐1‐yl)bis (butane‐1‐sulfonic acid) showed enhanced catalytic performance in the preparation of spiro[indeno[1,2‐b]quinoxaline derivatives in excellent yields. Moreover, this method showed several advantages such as mild conditions, high yields, easy work‐up, and being environmentally friendly. The catalyst can be easily separated from the reaction mixture by an external magnet, recycled, and reused several times without a noticeable decrease in catalytic activity.     

KAl(SO4)2·12H2O (Alum) Catalyzed One‐Pot Three‐Component Synthesis of 2‐Alkyl and 2‐Aryl‐4(3H)‐quinazolinone under Microwave Irradiation and Solvent Free Conditions

Twenty 2,3‐disubstituted‐4(3H)‐quinazolinones were synthesed by one‐pot three‐component method with isatoic anhydride, orthoesters and amines as raw materials in the presence of KAl(SO₄)₂·12H₂O (Alum) under microwave irradiation and solvent‐free conditions. 6‐Bromo‐2‐propyl‐3‐p‐tolylquinazolin‐4(3H)‐one ( 4m ), 6‐bromo‐2‐methyl‐3‐phenethylquinazolin‐4(3H)‐one ( 4n ) and 6‐bromo‐2‐ethyl‐3‐phenethylquinazolin‐4(3H)‐one ( 4o ) were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis.     

Novel One‐Pot Three‐Component Reaction for the Synthesis of Functionalized Spiroquinazolinones

A wide variety of spiroquinazolinone derivatives have been synthesized via a one‐pot three‐component reaction of isatoic anhydride, cyclic ketones, and hydrazides in the presence of catalytic amount (20 mol%) of H₃PO₃ in ethanol. Mild reaction conditions, high atom economy, operational simplicity, and good to high yields are the key advantages of the present protocol.