Cesium carbonate catalyzed efficient synthesis of quinazoline-2,4(1H,3H)-diones using carbon dioxide and 2-aminobenzonitriles

Abstract

An efficient protocol for the synthesis of quinazoline-2,4(1H,3H)-diones derivatives from 2-aminobenzonitriles with carbon dioxide using catalytic amount of cesium carbonate has been developed. 6,7-Dimethoxyquinazoline-2,4(1H,3H)-dione, which is one of the key intermediate for the synthesis of several drugs (Prazosin, Bunazosin and Doxazosin) was synthesized. The effect of different reaction parameters like influences of bases, solvent, temperature, CO₂ pressure and reaction time were investigated for the title reaction.     

Green chemistry approach to the synthesis of 3-substituted-quinazolin-4(3H)-ones and 2-methyl-3-substituted-quinazolin-4(3H)-ones and biological evaluation

ABSTRACT

A synthesis of two series of 3-substituted quinazolinones was performed utilizing a green chemistry approach, deep eutectic solvents and microwaves, namely. 2-Methyl-3-substituted-quinazolin-4(3H)-one derivatives were synthesized in a two-step reaction, using choline chloride:urea deep eutectic solvent (DES). 3-Substituted-quinazolin-4(3H)-ones were synthesized in one-pot one-step reaction of anthranilic acid, amines and orthoester in a microwave reactor. For the synthesis of 2-methyl-3-substituted-quinazolin-4(3H)-ones, first conventional synthesis of benzoxazinone, as an intermediate, was performed. Further, benzoxazinone in reaction with corresponding amines, in choline choline:urea deep eutectic solvent, furnished desired compounds. These procedures are based on green principles with the aim of developing synthetic routes for the potential antitumor agents. All compounds were characterized by LC/MS, ¹H NMR and ¹³C NMR spectral techniques. Compound 1 bearing trifluoromethoxyphenyl group showed promising activity against HuT-78 cell line with IC₅₀ of 51.4?±?5.1?µM.     

An Efficient Synthesis of Highly Optically Active 4-Substituted-2（5H）-furanones from Chiral 3-Bromo-2（5H）-furanone

Highly optically active 4-substituted-2(5H)-furanones 6a-6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(SH)-furanone (4a), which was conveniently prepared starting from 2-furaldehyde under mild conditions. The products were identified on the basis of their satisfactory elemental analysis and spectroscopic data of IR, UV, ^1H NMR, ^13C NMR and mass spectra. The stereochemistry and absolute configuration of this type of compounds were established by the X-ray crystallographic study. The reaction provided a short and efficient synthesis of the interesting highly optically active 4-subsdtuted-2(5H)-furanones containing an active pyrimidine and a purine base group.     

New domino‐reaction for the synthesis of N4‐(5‐aryl‐1,3‐oxathiol‐2‐yliden)‐2‐phenylquinazolin‐4‐amines and 4‐[4‐aryl‐5‐(2‐phenylquinazolin‐4‐yl)‐1,3‐thiazol‐2‐yl]morpholine

The model morpholine‐1‐carbothioic acid (2‐phenyl‐3H‐quinazolin‐4‐ylidene) amide (1) reacts with phenacyl bromides to afford N⁴‐(5‐aryl‐1,3‐oxathiol‐2‐yliden)‐2‐phenylquinazolin‐4‐amines (4) or N⁴‐(4,5‐diphenyl‐1,3‐oxathiol‐2‐yliden)‐2‐phenyl‐4‐aminoquinazoline ( 5 ) by a thermodynamically controlled reversible reaction favoring the enolate intermediate, while the 4‐[4‐aryl‐5‐(2‐phenylquinazolin‐4‐yl)‐1,3‐thiazol‐2‐yl]morpholine ( 8 ) was produced by a kinetically controlled reaction favoring the C‐anion intermediate. ¹H nmr, ¹³C nmr, ir, mass spectroscopy and x‐ray identified compounds ( 4 ), ( 5 ) and ( 8 ).     

New Approaches to the Synthesis of 4‐(2‐Aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones and 3‐Ureidoindoles and a Study of Their Interconversion

3‐Alkyl/aryl‐3‐ureido‐1H,3H‐quinoline‐2,4‐diones ( 2 ) and 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1H‐imidazo[4,5‐c]quinoline‐2,4‐diones ( 3 ) react in boiling concentrated HCl to give 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones ( 6 ). The same compounds were prepared by the same procedure from 2‐alkyl/aryl‐3‐ureido‐1H‐indoles ( 4 ), which were obtained from the reaction of 3‐alkyl/aryl‐3‐aminoquinoline‐2,4(1H,3H)‐diones ( 1 ) with 1,3‐diphenylurea or by the transformation of 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1H‐imidazo[4,5‐c]quinoline‐2,4‐diones ( 3 ) and 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones ( 6 ) in boiling AcOH. The latter were converted into 1,3‐bis[2‐(2‐oxo‐2,3‐dihydro‐1H‐imidazol‐4‐yl)phenyl]ureas ( 5 ) by treatment with triphosgene. All compounds were characterized by ¹H‐ and ¹³C‐NMR and IR spectroscopy, as well as atmospheric pressure chemical‐ionisation mass spectra.     

Synthesis of 2-(4-amino substituted benzylidene) indanone analogues from aromatic nucleophilic substitution (SNAr) reaction

A novel, efficient and convenient procedure has been developed for the synthesis of 2-(4-amino-substituted benzylidene)indanone derivatives. In the first step, the reaction of 4-fluorobenzaldehyde with 5, 6-dimethoxy-2, 3-dihydro-1H-inden-1-one in the presence of NaOH in EtOH was described. In the next step, a variety of aliphatic and aromatic amines were reacted with 2-(4-fluorobenzylidene)-5, 6-dimethoxy-2, 3-dihydro-1H-Inden-1-one via aromatic substitution (S_NAr) reaction to produce 2-(4-aminobenzylidene)-5, 6-dimethoxy-2, 3-dihydro-1H-Inden-1-one derivatives as a novel class of 1-indanones. These products have been successfully prepared in good to excellent yields. ^1?H and ^13?C NMR, FT-IR spectroscopy and CHN analysis supported the proposed structures of the products.     

Biomimetic synthesis of 4-acetylbenzoxazolin-2(3H)-one isolated from Zea mays

4-Acetylbenzoxazolin-2(3H)-one has been prepared biomimetically during attempts to synthesize the hemiacetalic hydroxamic acid 5-acetyl-2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one by the immediate degradation of this unstable compound generated as an intermediate. Thus, 4-acetylbenzoxazolin-2(3H)-one recently isolated from Zea mays kernels, and similar to other benzoxazolin-2(3H)-ones known from plant sources, is assumed to have originated from the degradation of natural 5-acetyl-2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one which in turn could have been enzymatically released by a β-glucosidase from the corresponding 2-β-D-glucoside.     

Efficient and facile synthesis of 5-arylindeno[2′,1′:5,6]pyrido[2,3-d] pyrimidine-2,4(3H)-dione and 7-arylbenzo[h]pyrimido[4,5-b]quinoline-8,10(5H,9H)-dione under mild conditions

An efficient and facile method for the synthesis of 5-arylindeno[2′,1′:5,6]pyrido[2,3-d] pyrimidine-2,4(3H)-dione and 7-arylbenzo[h]pyrimido[4,5-b]quinoline-8,10(5H,9H)-dione derivatives from the reactions of 2-arylidene-2,3-dihydroinden-1-one (or 2-arylidene-3,4- dihydronaphthalen-1(2H)-one) and 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione under mild conditions was described. This is a simple, efficient, and very rapid synthetic method, which is believed to provide a useful process for the synthesis of these fused heterocyclic compounds. The products were confirmed by infrared, ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry.     

Synthesis of 3-(3-Methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one Derivatives via a One-Pot,Three-Component Reaction

An efficient synthesis of 3-(3-methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one derivatives by the reaction of salicylaldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one, and arylhydrazine in acetonitrile under reflux condition and in the presence of piperidine is reported. This three-component reaction has some advantages such as ease of handling, good yields, and easy purification. All structures were confirmed by infrared, mass, ¹H NMR, and ¹³C NMR spectroscopy.     

A Novel and Efficient Synthesis of 3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐ones (=3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐1‐benzopyran‐2‐ones)

An efficient one‐pot synthesis of 3‐[(4,5‐dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐one (=3‐[(4,5‐dihydro‐1H‐pyrrol‐3yl)carbonyl]‐2H‐1‐benzopyran‐2‐one) derivatives 4 by a four‐component reaction of a salicylaldehyde 1 , 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one, a benzylamine 2 , and a diaroylacetylene (=1,4‐diarylbut‐2‐yne‐1,4‐dione) 3 in EtOH is reported. This new protocol has the advantages of high yields (Table), and convenient operation. The structures of these coumarin (=2H‐1‐benzopyran‐2‐one) derivatives, which are important compounds in organic chemistry, were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).     

Synthesis of Some Novel 5-(Arylidene)-2-imino-3(pyridin-2-yl)thiazolidin-4-one Derivatives

Treatment of 2-aminopyridine ( 1 ) with chloroacetyl chloride in dry benzene gave 2-chloro-N-(pyridin-2-yl)acetamide ( 3 ), which on further reaction with potassium thiocyanate gave 2-imino-3-(pyridin-2-yl)thiazolidin-4-one ( 4 ) as an intermediate compound for the synthesis of pyridin-2-yl substituted 2-imino-thiazolidine-4-one derivatives. Cyclocondensation reaction of ( 4 ) with a series of aromatic aldehydes gave 5-arylidene derivatives of pyridin-2-yl substituted 2-imino-thiazolidine-4-ones 5a–j . ¹ H and ¹³C NMR spectroscopy, as well as elemental analyses, were used for the identification of these new compounds.     

Elucidating heteroatom influence on homonuclear 4J(H,H) coupling constants by DFT/NMR approach

We report the structural dependency of long range scalar J-coupling constant across four bonds as function of the dihedral angles Φ1 and Φ3. The calculated homonuclear coupling constants ⁴J(_H,H), obtained at a density functional theory level, were measured between C(1)─X(2) and X(2)─C(3) bonds in three-term models, where C, N, O, and S were systematically used as the second atom of the alkyl structures ( 1 - 4 ). The ⁴J_(H,H) calculated values, tabulated for variation of 30° for both Φ1 and Φ3, have disclosed an unexpected detectable coupling constant (⁴J(_H,H) ≥ 1 Hz) across heteroatoms, useful to provide valuable structural information. A 2-methyl-1,3-dithiane sulfide ( 5 ) was used as a case study to prove the applicability and reliability of the calculated values to real issues. The ⁴J(_H,H) values obtained at density functional theory for the system 4 have reproduced with good accuracy an unexpected experimental ⁴J(_H2ax-H4ax) = 1.01 Hz of sulfide molecule ( 5 ), suggesting these calculated coupling constant values as a new powerful tool for the organic synthesis and stereochemical analysis.     

Reaction of 3‐Hydroxyquinoline‐2,4‐diones with Isocyanates and Thermally Induced Transformation of the Reaction Products

3‐Hydroxyquinoline‐2,4‐diones 1 react with isocyanates to give novel 1,2,3,4‐tetrahydro‐2,4‐dioxoquinolin‐3‐yl (alkyl/aryl)carbamates 2 and/or 1,9b‐dihydro‐9b‐hydroxyoxazolo[5,4‐c]quinoline‐2,4(3aH,5H)‐diones 3 . Both of these compounds are converted, by boiling in cyclohexylbenzene solution in the presence of Ph₃P or 4‐(dimethylamino)pyridine, to give 3‐(acyloxy)‐1,3‐dihydro‐2H‐indol‐2‐ones 8 . All compounds were characterized by IR, and ¹H‐ and ¹³C‐NMR spectroscopy, as well as by EI mass spectrometry.     

CoNiFe2O4@Silica-SO3H nanoparticles: New recyclable magnetic nanocatalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones under solvent-free conditions

A useful and green synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones derivatives were achieved by one-pot cyclocondensation between substituted aryl aldehydes, diketone/ketoester, and urea/thiourea using magnetic CoNiFe₂O₄@Silica-SO₃H nanoparticles under solvent-free condition. The choice of this approach showed essential advantages such as short reaction time, simple work-up procedure, high activity of the catalyst, high yield of the reaction products, the magnetic properties of the catalyst, and environmentally amiable conditions. In addition, the catalyst recovered and reused four times without notable loss of its activity. The magnetic CoNiFe₂O₄@Silica-SO₃H nanoparticles were described by Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, and vibrating sample magnetometer. The products were obtained with excellent yields (88–98%). The formation of the products was confirmed and identified with their physical properties (melting points), the FT-IR, ¹H NMR, ¹³C NMR, mass spectrometry, and the elemental analysis.     

Synthesis of a Novel Series of 2,3‐Disubstituted Quinazolin‐4(3H)‐ones as a Product of a Nucleophilic Attack at C(2) of the Corresponding 4H‐3,1‐Benzoxazin‐4‐one

A new series of 2,3‐disubstituted quinazolin‐4(3H)‐one derivatives was synthesized by nucleophilic attack at C(2) of the corresponding key starting material 2‐propyl‐4H‐3,1‐benzoxazin‐4‐one (Scheme 2). The reaction proceeded via amidinium salt formation (Scheme 3) rather than via an N‐acylanthranilimide. The structure of the prepared compounds were elucidated by physical and spectral data like FT‐IR, ¹H‐NMR, and mass spectroscopy.     

Umsetzungen von 3-(Dimethylamino)-2,2-dimethyl-2H-azirin mit Barbitursäure-Derivaten

Reactions of 3-(Dimethylamino)-2,2-dimethyl-2H-azirines with Barbituric-Acid Derivatives The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine ( 1 ) and 5,5-disubstituted barbituric acids 5 in i-PrOH at ca. 70° gives 2-[5-(dimethylamino)-4,4-dimethyl-4H-imidazol-2-yl]alkanamides of type 6 in good yields (Scheme 1). The formation of 6 proceeds with loss of CO₂; various reaction mechanisms with a zwitterionic 1:1 adduct B as common intermediate are discussed (Schemes 2 and 5). Thermolysis of product 6 leads to 2-alkyl-5-(dimethylamino)-4,4-dimethyl-4H-imidazoles 8 or the tautomeric 2-alkylidene derivatives 8 ′ via elimination of HNCO (Scheme 3). The latter undergoes trimerization to give 1,3,5-triazine-2,4,6-trione. No reaction is observed with 1,5,5-trisubstituted barbiturates and 1 in refluxing i-PrOH, but an N-alkylation of the barbiturate occurs in the presence of morpholine (Scheme 4). This astonishing reaction is explained by a mechanism via formation of the 2-alkoxy-2-(dimethylamino )aziridinium ion H which undergoes ring opening to give the O-alkylated 2-amino-N¹,N¹-dimethylisobutyramide I as alkylating reagent (Scheme 4).     

New synthesis and reactivity of 3‐bromoacetyl‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one with binucleophilic amines

3‐(Bromoacetyl)‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one was synthesized by the reaction of dehydroacetic acid (DHAA) with bromine in glacial acetic acid. Novel heterocyclic products were synthesized from the reaction of bromo‐DHAA with alkanediamines, phenylhydrazines, ortho‐phenylenediamines, and ortho‐aminobenzenethiol. The obtained new products 3‐(2‐N‐substituted‐acetyl)‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐ones, 4‐hydroxy‐3‐[1‐hydroxy‐2‐(2‐phenylhydrazinyl)vinyl]‐6‐methyl‐2H‐pyran‐2‐one, 1‐(2,4‐dinitrophenyl)‐7‐methyl‐2,3‐dihydro‐1H‐pyrano[4,3‐c]pyridazine‐4,5‐dione, 3‐(3,4‐dihydroquinoxalin‐2‐yl)‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one/3‐(3,4‐dihydroquinoxalin‐2‐yl)‐6‐methyl‐2H‐pyran‐2,4(3H)‐dione, 6‐methyl‐3‐(3,4‐dihydroquinoxalin‐2‐yl)‐2H‐pyran‐2,4(3H)‐dione, and (E)‐3‐(2H‐benzo[b][1,4]thiazin‐3(4H)‐ylidene)‐6‐methyl‐2H‐pyran‐2,4(3H)‐dione were fully characterized by IR, ¹H and ¹³C NMR, and mass spectra. J. Heterocyclic Chem., 2011.     

Green synthesis of 4,6-bisarylpyrimidin-2(1H)-ones and azo-linked 4-arylpyrimidin-2(1H)-ones using NiFe2O4@SiO2nPr@glucose amine as a mild nano catalyst

The clean, environmentally benign and effective synthesis of novel azo-linked 4-arylpyrimidin-2(1H)-one derivatives and 4,6-bisarylpyrimidin-2(1H)-ones via three-component reaction of various aldehydes or synthetized azo-linked aldehydes, urea, and acetophenone promoted by NiFe₂O₄@SiO₂ⁿPr@glucose amine at room temperature (25 °C) was reported. NiFe₂O₄@SiO₂ⁿPr@glucose amine were synthesized and characterized by transmission electron microscope (TEM), fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), X-ray powder diffraction (XRD) and X-ray spectroscopy (EDX). These compounds were obtained in high yields and short reaction times. The catalyst could be easily recovered and reused for six cycles with almost consistent activity. The structures of the synthesized 4,6-bisarylpyrimidin-2(1H)-one compounds were confirmed by ¹H NMR, ¹³C NMR and FTIR spectral data and elemental analyses.     

A facile synthesis of 8-(β-D-ribofuranosyl)-4-thioxo-3H-pyrazolo[1,5-a]-1,3,5-triazine and its α-anomer

A versatile intermediate 2 for C-nucleoside synthesis was treated with thiosemicarbazide to obtain thiosemicarbazone 6 , which was then converted to 3-aminopyrazol-2N-thiocarboxamide derivatives 7 and 8 by the reaction of 6 and sodium ethoxide. 4-Thioxo-4H-pyrazolo[1,5-a]-1,3,5-triazine C-nucleosides 11 and 12 were obtained by the ring closure reaction of 7 and 8 with triethyl orthoformate. Brief treatment of 11 and 12 with 10% methanolic hydrogen chloride afforded C-nucleosides 4 and 13 , respectively, without anomerization. Identification of compounds 4 and 13 was made on the basis of ¹H nmr and uv spectra, as well as chemical conversion to known compounds with established configurations. Model compounds were also synthesized in order to confirm the heterocyclic moieties.     

2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides and their regioselective N4-methylation and -amination

The syntheses of 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides and 1,1-dioxides is described. The reaction of 1-carbamoyl-2-methylisothioureas 2 with thionyl chloride gave 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides 3 in high yields. The treatment of 3 with either diazomethane or O-(2,4-dinitrophenyl)hydroxylamine furnished regioselectively N⁴-methylated and N⁴-aminated 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides, respectively. Subsequent dimethylamination of 4 followed by oxidation with m-chloroperoxybenzoic acid led to 2H-1,2,4,6-thiatriazin-3(4H)-one 1,1-dioxides 6a-c .