Réactions de friedel-crafts de dérivés aromatiques sur des composés dicarbonylés-1,4éthyléniques-2,3.ii alkylations par quelques hydroxy-5 ou chloro-5 dihydro-2,5 furannones-2. nouvelle méthode de synthèse des acides 1h-indènecarboxyliques-1

With acid catalysts, 3,4-dimethyl-5-hydroxy (or 5-chloro)-2-(5H)furanones substituted at position 5, react with aromatic derivatives to give the corresponding 5-aryl-3,4-dimethyl-2(5H)-furanones in a first step. Some of these 5-aryl furanones are able to isomerize into 1H-indenecarboxylic acids by ring-opening, allylic-type-transposition, and intramolecular alkylation. The nature of the catalyst is important: sulfuric acid leads to the 5-aryl furanones, while aluminium chloride leads in one step, to indenecarboxylic acids. This type of reaction is fairiy general. Reaction mechanisms are proposed and discussed.     

Regioselective synthesis of cytotoxic 4-(1-alkynyl)-substituted 2-(5H)-furanones

4-(1-Alkynyl)-3-bromo- and 4-(1-alkynyl)-3-chloro-2(5H)-furanones have been regioselectively synthesized in moderate to good yields by a new version of the Pd/Cu-catalyzed Sonogashira reaction involving treatment of 1-alkynes with 3,4-dibromo- and 3,4-dichloro-2(5H)-furanone, respectively, in the presence of KF as a base. 4-(1-Alkynyl)-3-bromo-2(5H)-furanones have been found to be able to undergo Stille-type and Suzuki-type reactions with aryl(tributyl)tins and arylboronic acids, respectively, to give 4-(1-alkynyl)-3-aryl-2(5H)-furanones in modest to satisfactory yields. Some 4-(1-alkynyl)-substituted 2(5H)-furanones so prepared have been found to exhibit significant cytotoxic activities, especially against human leukemia cell lines.     

An efficient procedure for the synthesis of 3-aryl-4-methoxy-2(5H)-furanones by using the microwave-promoted Suzuki-Miyaura coupling reactions

The Suzuki-Miyaura coupling reactions of 3-bromo-2(5H)-furanones with a variety of arylboronic acids, promoted by microwave heating, efficiently generate 3-aryl-2(5H)-furanones. This remarkably rapid process serves as the foundation for a simple method to rapidly construct 3-aryl-2(5H)-furanone libraries.     

2-Amino-4-aryl-6-(ω-carboxyalkyl)-5H-pyrrolo[3,4-d]pyrimidin-7-(6H)ones. Preparation via a one-pot synthesis of 1-(ω-carboxyalkyl)-4-carbethoxy-2,3-dioxopyrrolidines

1-(ω-Carboxyalkyl)-4-carboethoxy-2,3-dioxopyrrolidines were prepared by a one-pot synthesis from β-alanine or γ-aminobutyric acid, ethyl acrylate and diethyl oxalate. In a second one-pot process these products were hydrolyzed, decarboxylated and condensed with aromatic aldehydes under the influence of hydrochloric acid to yield 1-(ω-carboxyalkyl)-4-arylidene-2,3-dioxo-pyrolidines, which yielded 2-amino-4-aryl-6-(ω-carboxyalkyl)-5H-pyrrolo[3,4-d]pyrimidin-7-(6H)-ones upon treatment with guanidine. It was shown that 3,4-dihydro derivatives of certain 2-amino-4-aryl-5H-pyrrolo[3,4-d]pyrimidin-7-(6H)ones, formed initially in the guanidine reaction, readily undergo conversion to 5H-pyrrolo[3,4-d]pyrimidin-7-(6H)ones.     

Reaction of 5-arylfuran-2(3<Emphasis Type="Italic">H</Emphasis>)-ones with amines

5-(4-Chlorophenyl)- and 5-phenylfuran-2(3H)-ones reacted with guanidine carbonate at the methylene group in the unsaturated lactone molecule, leading to the formation of 4-(2-aryl-5-oxo-2,5-dihydrofuran-2-yl)-5-aryltetrahydrofuran-2-ones, while 5-(4-methylphenyl)furan-2(3H)-one under analogous conditions gave rise to N,N′-bis[4-(4-methylphenyl)-4-oxobutanoyl]guanidine. The reactions of 5-arylfuran-2(3H)- ones with thioacetamide afforded 4-aryl-N-{1-[5-aryl-2-oxo-2,3-dihydrofuran-3-ylidene]ethyl}-4-oxobutanamides. The corresponding N-(4-aryl-4-oxobutanoyl)thioureas were obtained by heating 5-arylfuran-2(3H)-ones with thiourea.     

Etude en série triazénique. IV. Synthèse et réactivité d'aryl-3-(diméthyl-3,4-isoxazolyl-5)-1-triazènes et d'arylazo-4-diméthyl-3,4-isoxazolones-5

Synthesis and reactivity of 3-aryl-1-(3,4-dimethyl-5-isoxazolyl)-triazenes and 4-arylazo-3,4-dimethylisoxazol-5-ones According to the experimental conditions and the nature of the substituents on the aromatic ring, aryldiazonium salts react with 5-amino-3,4-dimethylisoxazole ( 3 ) leading to either 3-aryl-1 (3,4-dimethyl-5-isoxazolyl)-triazenes ( 1A ) or 4-arylazo-3,4-dimethylisoxazol-5-ones ( 4 ). Analyses of the products resulting from thermal decomposition of these triazenes in aromatic substrates and in DMSO and their behaviour in acidic medium show that it is essentially the arylazo form 1B which is reactive.     

Synthesis of 3-acylamino-2-oxazolidinone derivatives through cyclic transformations of 5-aryl (or benzyl)-1,3,4-oxadiazol-2(3H)-one derivatives

New 3-acylamino-2-oxazolidinone derivatives 3 were obtained in good yields by reaction of 5-aryl (or benzyl)3-(2-hydroxyethyl)1,3,4-oxadiazol-2(3H)ones 1 with sodium ethylate. Treatment of ethyl 5-aryl-2-oxo-1,3,4-oxadiazole-3(2H)-acetates 7 with aromatic aldehydes in the presence of sodium ethylate or sodium hydride afforded 3-acylamino-5-aryl-4-ethoxycarbonyl-2-oxazolidinone derivatives as two trans- 5 and cis- 6 racemics. Only RS,SR-racemates were obtained with acetophenone under the same conditions.     

Régiospécificite et stéréosélectivite de la cycloaddition de l'oxyde de benzonitrile sur la phényl-5 A-3-pyrazoline

An example of stereospecific and stereoselective reactions is described concerning the cycloaddition of benzonitrile oxyde with 1,2-dimethyl-5-diphenyl-3-pyrazoline. The structure of the two epimeric 5,6-dimethyl 3,4-dimethyl[4,3-d]pyrazolidinoisoxazo-lines-2 was proved by the means of chemical and physical methods. The conversion of one epimeric product to another more stable is achieved and discussed.     

Reaction of 6-methoxybenzo[b]furan-3(2H)-one and benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes as a convenient synthetic route to substituted 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans and 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans

The reactions of 6-methoxybenzo[b]furan-3(2H)-one with 2-aryl-1,1-dicyanoethylenes and malononitrile or with aromatic aldehyde and two moles of malononitrile afford 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans. The reactions of benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes or with aromatic aldehyde and one mole of malononitrile produce 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans.     

Synthesis of 5-aryl-3-carbazoyl-1,3,4-oxadiazol-2(3H)-one. Derivatives and their ring transformation into 5-benzamido-1,2,4-triazolidine-3,5-dione derivatives

Some 5-aryl-3-carbazoyl-1,3,4-oxadiazol-2(3H)-one derivatives 6 and 9 have been synthesized in two ways. The expected thermal ring transformation into 2,5-disubstituted 1,3,4-oxadiazoles did not occur but, by acid hydrolysis of 5-aryl-3-[3-benzylidene-2-methyl(or phenyl)carbazoyl]-1,3,4-oxadiazol-2(3H)-ones 6 , a new ring transformation took place and the corresponding 4-benzamido-1-methyl(or phenyl)-1,2,4-triazolidine-3,5-dione derivatives 11 were formed. The 4-amino-1-phenyl-1,2,4-triazolidine-3,5-dione ( 19 ) has been prepared and its structure was confirmed by some reactions.     

Tetrazole compounds. 9. A new approach to tetrazolyl-substituted quinoline derivatives

The acid-catalyzed reaction of 1-aryl-5-(2-dimethylaminovinyl)-1H-tetrazoles 2 with arylamines suitably functionalized in the ortho-position resulted in Z-configurated transamination products which were cyclized to novel 3-tetrazolylquinolines by the action of sodium ethoxide. Thus, on reacting 2 with 2-aminoacetophenone or 2-aminobenzophenone, respectively, the 2-[2-(1-aryl-1H-tetrazol-5-yl)vinyl-amino]aryl ketones 3a-g were obtained, the cyclization of which gave 4-substituted 3-(1-aryl-1H-tetrazol-5-yl)quinolines 4 . In the case of the transamination products 3h-1 , prepared from 2 and methyl anthranilate, the ring closure afforded 3-(1-aryl-1H-tetrazol-5-yl)-1H-quinolin-4-ones 5 . Starting from 2 and anthranilonitrile 4-amino-3-(1-aryl-1H-tetrazol-5-yl)quinolines 10 were obtained via the corresponding intermediates 9 .     

Pyrimidones 1. Synthesis of some 1-substituted-5-aryl- and (4,5-diaryl)-2(1H)pyrimidones

A series of 1-substituted-5-aryl-2(1H)pyrimidones has been prepared by a method involving condensation of an appropriate N-substituted urea with either 2-aryl-3-(dimethylamino)-acroleins or 2-arylmalondialdehydes. On biological investigation, several compounds exhibited some antiinflammatory activity.     

Bromination-Dehydrobromination of 4-Aryl-5-nitro-6-phenyl-3,4-dihydropyrimidin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

Depending on the conditions, bromination of 4-aryl-5-nitro-6-phenyl-3,4-dihydropyrimidine-2(1H)-ones and subsequent dehydrobromination gives either 4-aryl-5-nitro-6-phenylpyrimidin-2(1H)-ones or their mixtures with the corresponding 4-aryl-5-bromo-6-methoxy-5-nitro-6-phenyltetrahydropyrimidin-2-ones which are formed as two diastereoisomers.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 425–430.Original Russian Text Copyright © 2005 by Sedova, Gatilov, Shkurko.     

[1]Benzothieno[2,3-d]pyridazines V. Etude des Réactions de substitution des Benzothiéno[2,3-d]pyridazinethiones

The substitution and addition reactions of the 2H[1]benzothiéno[2,3-d]phyridazinethione-1 and the 3H[1]benzothiéno[2,3-d]pyridazinethione-4 gave N- or S-substituted derivatives whose structures were identified by 1R and NMR spectroscopy.     

Synthèse énantiospécifique des acides (+)-(2R)- et (−)-(2S)-éthyl-6-dihydro-3,4-méthyl-2-oxo-4–2H pyranecarboxylique-5

Enantiospecific Synthesis of (+)-(2R)- and (?)-(2S)-6-Ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic Acid The two enantiomers (?)-(2S)- and (+)-(2R)-6-ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic acid ((S)- and (R)- 7 ) have been synthesized from (+)-(3S) and (?)-(3R)-3-hydroxybutanoates, respectively (Scheme 1). By reduction and decarboxylation, the tetrahydro-2H-pyranols (2R, 4R, 6S)- and (2S, 4S, 6R)- 13 , respectively, were obtained with an enantiomeric excess of ≥ 93%.     

Three-Component Condensation of Methyl Acylpyruvates with Aromatic Aldehydes and Ethylenediamine. Chemical Properties of the Products

Reactions of methyl acetyl- or benzoylpyruvates with aromatic aldehydes and ethylenediamine, depending on the reactant ratio, afforded 4-acyl-1-(2-aminoethyl)-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones or 1,2-bis(4-acyl-5-aryl-3-hydroxy-2-oxo-2,5-dihydro-1H-pyrrol-1-yl)ethanes. Substituted 1-(2-aminoethyl)-3-hydroxy-2,5-dihydro-1H-pyrrol-2-one hydrochlorides were brought into reactions with p-methoxyaniline and hydrazine.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005, pp. 282–287.Original Russian Text Copyright © 2005 by Gein, Kasimova.     

Composés sulfurés hétérocycliques. CII. Action de l'hydroxylamine sur les dihydro-1,2 benzothiazine-3,1 thiones-4

Hydroxylamine reacts with 1-alkyl-1,2-dihydro-3,1-benzothiazine-4thiones ( 1 ), giving 1-alky1-3-hydroxy-2,3-dihydro-1H-quinazoline-4-thiones ( 2 ). The same reagent, in neutral medium, converts 1-aryl-1,2-dihydro-3,1-benzothiazine-4-thiones ( 3 ) into 1-aryl-4-hydroxyimino-1,4-dihydro-2H-3,1-benzothiazines ( 4 ). In acidic medium, the same starting materials lead to 1-aryl-3-hydroxy-2-3-dihydro-1H-quinazoline-4-thiones ( 5 ). genrally with some quantity of the isomer 4 . Thiones 2 and 5 , as well as oximes 4 , heated at 200°, decomopose, yielding, in varying proportions, 1H-quinazoline-4-thiones ( 6 or 7 ), 1H-quinazoline-4-ones ( 9 ) and 2,3-dihydro-1H-quinazoline-4-thiones ( 11 ). Reacting with methyliodide, 1H-quinazoline-4-thiones ( 7 ) give 4-methylthioquinazolin-1-ium iodidies ( 12 ) which can be hydrolysed into 1H-quinazolin-4-ones ( 9 ). The latter are also obtained by reacting benzonitrile N-oxide with the corresponding thiones. 1-Aryl-1 H-quinazoline-4-thiones ( 7 ) react readily with nitrogen nucleophiles XNH₂ to give 1-aryl-4-imino-1,4-dihydro-quinazolines diversely substituted on the imino group. While thiones 7 are S- methylated by methyl iodide, the corresponding 1-aryl-1H-quinazolin-4-ones (9), with the same reagent, ungergo a N-methylation, yielding 1-aryl-3-methyl-4-oxo-3,4-dihydroquinazolin-l-ium iodides ( 18 ). Structure have been confirmed by uv, ir and nmr spectra.     

Reaction of 5-aryl-2-tosylmethylimino-2,3-dihydro-3-furanones with substitutedN-(benzylidene)benzylamines. Crystal structure of 1-benzyl-5-p-methoxyphenyl-2-(p-chlorobenzoyl)acetylimidazole

5-Aryl-2-aroylacetyl-1-benzylimidazoles were synthesized by treatment of 5-aryl-2-tosylmethylimino-2, 3-dihydro-3-furanones withN-(benzylidene)benzylamines containing electron-donating substitutents in the benzylidene moiety. The structure of 1-benzyl-5-p)-methoxyphenyl-2-(p-chlorobenzoyl)acetylimidazole was studied by X-ray diffraction.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2013–2016, October, 1995.     

Etude dans la série des radicaux hétérocycliques: partie XIV. Radicaux diméthyl-3, 4-isoxazolyl-5. Réactivité en série aromatique et hétéroaromatique: nouvelle voie d'accès à des diméthyl-3, 4-isoxazoles subsitués en C(5) par des groupements aryle et hétéroaryle

The aprotic decomposition of 5-amino-3, 4-dimethyl-isoxazole with excess isoamyl nitrite in aromatic solvents (alkylbenzenes, polyalkylbenzenes, anisole etc.) and in heteroaromatic solvents (thiophene, 2, 4-dimethylthiazole, pyridine, 4-alkylpyridines, dimethyl- and trimethyl-pyridines) leads to 5-aryl- and 5-heteroaryl-isoxazoles in yields of about 40%. This method provides a new way of obtaining 5-iodo-3, 4-dimethyl-isoxazole by the aprotic decomposition of the corresponding amine in the presence of iodine (yield: 30%). The relative reactivity of the 3,4-dimethylisoxazol-5-yl radical in alkyl benzenes, in anisole and in alkylpyridines is very similar to that of other heteroaromatic radicals with the radical site next to a sulfur or an oxygen atom. The radical shows electrophilic character because of the inductive effect of the oxygen atom. In the pyridine series an abnormally high percentage of 2-substitution occurs. This may be explained by a solvatation effect. The characteristic GLC., NMR. and MS. data are reported for most of the compounds studied.     

N-ethoxycarbonylamidines as starting materials and intermediates in the synthesis of heterocyclic compounds

Treatment of N-ethoxycarbonylthioamides ( 1 ) with primary aromatic amines yields N-aryl-N′-ethoxy-carbonylamidines ( 2 ), which thermally cyclize to 2-aryl-4(3H)-quinazolinones ( 6 ). Analogous reactions of 1 with ethyl 3-aminocrotonate and with 2-amino-2-thiazoline lead respectively to ethyl 2-aryl-3,4-dihydro-6-methyl-4-oxo-5-pyrimidinecarboxylates ( 10 ) and to 2-aryl-6,7-dihydro-4H-thiazolo[3,2-a]-1,3,5-triazin-4-ones ( 14 ), presumably through the corresponding N-ethoxycarbonylamidines.