Hydrogenolysis of the C?O bond of the 1,2,4-oxadiazine ring. Adams platinum hydrogenation of 3-aryl-5,6-dihydro-5-(substituted)-methylene-4H-1,2,4-oxadiazine derivatives

Adams platinum hydrogenation of Z-3-aryl-5,6-dihydro-5-(substituted)methylene-4H-1,2,4- oxadiazine ( 1a-f ) proceeds very slowly through C? O bond fission to give N-(1-substitutedcarbonyl-2-propylidene)benzamide ox-ime derivative 2 as the main product. In the reaction of 5-(arylcarbamoyl)methylene analogues 1d-f , 5-(aryl-carbamoyl)methyl-5,6-dihydro-3-phenyl-4H-1,2,4-oxadiazine ( 4 ) and N-aryl-3-hydroxybutanamide derivative 5 are also obtained as well as compound 2 .     

Five-Membered 2,3-Dioxo Heterocycles: L. Synthesis and Thermolysis of 3-Aroyl- and 3-Hetaroyl-5-phenyl-1,2,4,5-tetrahydropyrrolo[1,2-<Emphasis Type="Italic">a</Emphasis>]quinoxalin-1,2,4-triones

(Z)-3-Phenacylidene- and (Z)-3-hetaroylmethylidene-1-phenyl-1,2,3,4-tetrahydroquinoxalin-2-ones react with oxalyl chloride to give 3-acyl-5-phenyl-1,2,4,5-tetrahydropyrrolo[1,2-a]quinoxaline-1,2,4-triones. Thermolysis of the latter generates acyl(3-oxo-4-phenyl-3,4-dihydroquinoxalin-2-yl)ketenes which are stabilized via [4 + 2]-cyclodimerization followed by [1,3]-acylotropic shift to afford 4-acyl-3-acyloxy-2-(3-oxo-4-phenyl-3,4-dihydroquinoxalin-2-yl)-6-phenyl-5,6-dihydro-1H-pyrido[1,2-a]quinoxaline-1,5-diones.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1101–1108.Original Russian Text Copyright © 2005 by Bozdyreva, Smirnova, Maslivets.     

Unexpected Direction of Iodocyclization of 3-Allylthio-5-phenyl-4H-1,2,4-triazole

The reaction of 3-allylthio-5-phenyl-4H-1,2,4-triazole with iodine to give a mixture of 5,6-dihydro-5-iodomethyl-3-phenyl[1,3]thiazolo[2,3-c][1,2,4]triazole, 6,7-dihydro-6-iodo-3-phenyl-5H-[1,2,4]triazolo[3,4-b][1,3]thiazine, 5,6-dihydro-6-iodomethyl-2-phenyl[1,3]thiazolo[3,2-b][1,2,4]triazole, and 6,7-dihydro-6-iodo-2-phenyl-5H-[1,2,4]triazolo[5,1-b][1,3]thiazine has been studied. The structure of the products obtained was established using ¹H NMR spectroscopy of their dehydriodination products.     

Synthesis of 4-β-D-arabinofuranosyl-5,6-dihydro-2H-1,2,4-thiadiazin-3-one 1,1-dioxide and x-ray diffraction analysis of its 2′,3-anhydro precursor

Reaction of 2-amino-3′,5′-bis(O-tert-butyldimethylsilyl)-β- D -arabinofuran[1′,2′:4,5]-2-oxazoline with 2-chloroethylsulfonyl chloride in the presence of sodium bicarbonate followed by removal of the protecting groups gave 2′,3-anhydro-4-β- D -arabinofuranosyl-5,6-dihydro-2H-1,2,4-thiadiazin-3-one 1,1-dioxide ( 5 ), which by treatment with ammonia was converted to 4-β- D -arabinofuranosyl-5,6-dihydro-2H-1,2,4-thiadiazin-3-one 1,1-dioxide ( 6 ). The structure of compound 5 was unequivocally established by means of an x-ray diffraction analysis. The compound crystallized in the space group P2₁2₁2₁ with unit cell dimensions a = 5.883(3), b = 9.352(2), c = 18.769(7) Å, Z = 4. Its structure was established by direct multisolution techniques and refined by the full matrix least squares method to a final R value of 0.058 for the 1515 reflections observed.     

Direct introduction of heterocyclic residues into 1,2,4-triazin-5(2H)ones

3-Aryl-1,2,4-triazin-5(2H)-ones 1a-c react with indoles 2a-c in trifluoroacetic acid/chloroform or in boiling butanol or acetic acid to give 3-aryl-6-(indolyl-3)-1,6-dihydro-1,2,4-triazin-5(2H)-ones 3a-g . Oxidation of the dihydro-1,2,4-triazin-5(2H)-ones 3a-e afforded 6-(indolyl-3)-1,2,4-triazin-5(2H)-ones 4a-e , products of nucleophilic substitution of hydrogen in 1a-c . Refluxing 1b with N-methylpyrrote 5b in butanol for an extended time resulted in the formation of 3-(4-chlorophenyl)-6-(1-meuiylpyrrolyl-2)-1,2,4-triazin-5(2H)-one 4h. The reaction of 1a-c with indoles 2a-c , pyrroles 5a,b , 1,3-dimethyl-2-phenylpyrazol-4-one (8) and aminothiazoles 9a,b in acetic anhydride affords the 1-acetyl-3-aryl-6-hetaryl-1,6-dihydro-1,2,4-triazin-5(2H)-ones 6a-s . Reaction of 1a-c with N-methyl-pyrrole 5b in acetic anhydride gives beside the 1:1 addition products 6h-k also the 2:1 addition products 7a-c .     

Reaction of 2-Aryl-5-R-5,6-dihydro-7H-[1,2,4]-triazolo[5,1-<Emphasis Type="Italic">b</Emphasis>][1,3]thiazin-7-ones with Aryl Bromomethyl Ketones and Benzyl Bromide

The products of the reaction of 2-aryl-5-R-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones with aryl bromomethyl ketones are 2-aryl-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones and aryl methyl ketones or 2,5-diaryl[1,3]thiazolo[3,2-b][1,2,4]triazoles and 3-phenyl-2-propenoic acid, depending on the structure of R. The reaction of 2-aryl-5-R-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones with benzyl bromide yields 5-aryl-3-benzylthio-4H-1,2,4-triazoles and 3-aryl-2-propenoyl bromide. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 905–909, June, 2005.     

Cycloacylation of <Emphasis Type="Italic">N</Emphasis>-Phenyl-3-oxobutanethioamide with 3-Aryl-2-propenoyl Chlorides

Reactions of N-phenyl-3-oxobutanethioamide with 3-aryl-2-propenoyl chlorides in acetone in the presence of potassium carbonate give rise to 4-aryl-5-acetyl-1-phenyl-6-thioxopiperidin-2-ones, 2-aryl-5-acetyl-6-phenylamino-2,3-dihydro-4H-thiopyran-4-ones, and 6-aryl-2-acetonylidene-3-phenyl-5,6-dihydro-4H-1,3-thiazin-4-ones whose structure was proved both by spectral methods and chemical transformations.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 2, 2005, pp. 292–296.Original Russian Text Copyright © 2005 by Britsun, Borisevich, Samoilenko, Lozinskii.     

Synthesis of 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones and their conversion into 2-aryl-1,2,4-triazine-3,5-(2H,4H)odiones. A new synthesis of 1-aryl-6-azauracils

Treatment of 6-amino-5-arylazo-1,3-dimethyluracils with urea or N,N′-carbonyldiimidazole gave the respective 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones, which were hydrolyzed with alkali to afford 2-aryl-2,3,4,5-tetrahydro-3,5-dioxo-1,2,4-triazine-6-carboxylic acids (1-aryl-6-azauracil-5-carboxylic acids). Thermal decomposition of these carboxylic acids gave the corresponding 2-aryl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-6-azauracils). Methylation of the latter with methyl iodide gave the corresponding 2-aryl-4-methyl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-3-methyl-6-azauracils).     

Synthesis and Transformations of 2-R-5-Aryl-5,6-dihydro-7H-[1,2,4]-triazolo[5,1-b][1,3]thiazin-7-ones

A new procedure for preparation of 2-R-5-aryl-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by condensation of 5-R-1,2,4-triazole-3-thiones with 3-arylacryloyl chlorides was developed. The thiazine ring of the [1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones is easily cleaved by treating with ammonia and hydrazine affording amides and hydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids. The latter react with isothiocyanates furnishing carbamoyl thiohydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids that in alkaline media undergo cyclization into 4-aryl-5-[2-(4H-1,2,4-triazol-5-ylsulfanyl)-2-phenylethyl]-2,4-dihydro-3H-1,2,4-triazole-5-thiones.     

Study of the Products of Iodocyclization of 4-Allyl-5-phenyl-1,2,4-triazole-3-thione

The interaction of 4-allyl-5-phenyl-1,2,4-triazole-3-thione with iodine proceeds with the formation of a mixture of 6-iodomethyl-3-phenyl-5,6-dihydrothiazolo[2,3-c]-1,2,4-triazole and 6-iodo-3-phenyl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b]-1,3-thiazine. The structures of the cyclization products obtained were established on the basis of the ¹H NMR spectra of their dehydroiodinated derivatives. 6-Methyl-3-phenylthiazolo[2,3-c]-1,2,4-triazole, 3-phenyl-5H-1,2,4-triazolo[3,4-b]-1,3-thiazine, and 3-phenyl-7H-1,2,4-triazolo[3,4-b]-1,3-thiazine are formed on eliminating HI from the cyclization products.     

Aminolysis of 2-Aryl-5-R-5,6-dihydro-7H-[1,2,4]triazolo[5,1-<Emphasis Type="Italic">b</Emphasis>]1,3]thiazin-7-ones

We have established that the products of aminolysis of 2-aryl-5-R-5,6-dihydro-7H-[1,2,4]triazolo-[5,1-b][1,3]thiazin-7-ones in boiling ethanol are 3-R-3-(5-aryl-4H-1,2,4-triazol-3-ylsulfanyl)-propanamides, and at 180°C–210°C (depending on the structure of the substituent R): 3-phenyl-4,5-dihydro-1H-1,2,4-triazoline-5-thione and 3-arylacrylamides or 3-(3-aryl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)propanamides. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1587–1592, October, 2005.     

Synthesis and Transformations of 5-Substituted 2-Aryl-7H-[1,2,4]triazolo[3,2-b][1,3]thiazin-7-ones and 2-Aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones

3-Aryl-1,2,4-triazole-5-thiones react with dimethyl acetylenedicarboxylate and methyl 3-phenyl-propynoate to afford the corresponding 5-substituted 2-aryl-7H-[1,2,4]triazolo[3,2-b][1,3]thiazin-7-ones. Treatment of 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones with alkalies leads to formation of 3-(benzimidazol-2-ylsulfanyl)-3-arylpropionic acids, their reaction with methyl p-toluenesulfonate yields 1-(3-methyl-2-thioxo-2,3-dihydro-1N-benzimidazol-1-yl)-3-phenyl-2-propen-1-one, and oxidation with hydrogen peroxide gives benzimidazole-2-sulfonic acid and 3-aryl-2-propenoic acids.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 109–114.Original Russian Text Copyright © 2005 by Britsun, Esipenko, Chernega, Lozinskii.     

Five-Membered 2,3-Dioxo Heterocycles: XLV. Thermolysis of 5-Aryl-4-phenyl-2,3-dihydrofuran-2,3-diones in the Absence of Other Partners and in the Presence of Carbonyl Compounds

Aroyl(phenyl)ketenes generated by thermolysis of 5-aryl-4-phenyl-2,3-dihydrofuran-2,3-diones undergo [4+2]-cyclodimerization to 3-aroyl-6-aryl-3,5-diphenyl-3,4-dihydro-2H-pyran-2,4-diones. Heating of the latter leads to rearrangement with formation of 4-aroyloxy-6-aryl-3,5-diphenyl-2H-pyran-2-ones. Thermolysis of 5-aryl-4-phenyl-2,3-dihydrofuran-2,3-diones in the presence of carbonyl compounds yields 6-aryl-5-phenyl-4H-1,3-dioxin-4-ones.     

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.     

2-{5-[(1H-1,2,4-三唑-1-基)甲基]-4-苯基-4H-1,2,4-三唑-3-硫基}-1-芳基乙酮类化合物的合成、表征及生物活性测试

通过α-卤代芳基乙酮和5-[(1H-1,2,4-三唑-1-基)甲基]-4-苯基-2H-1,2,4-三唑-3(4H)-硫酮反应, 合成了11个新的2-{5-[(1H-1,2,4-三唑-1-基)甲基]-4-苯基-4H-1,2,4-三唑-3-硫基}-1-芳基乙酮类化合物. 其结构经元素分析, IR, ¹H NMR等确证, 并用X射线单晶衍射测定了化合物6f的晶体结构. 生物活性测试结果表明, 部分化合物具有一定的杀菌活性.     

Intramolecular cyclization of 4-amino-3-alkylsulfanyl-1,2,4-triazoles as a method for annelation of thiadiazine and thiadiazole rings

4-Amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiols reacted with N-substituted isatins to give 2-oxo-3-[5-(pyridin-4-yl)-3-sulfanyl-4H-1,2,4-triazole-4-ylimino]-2,3-dihydro-1H-indoles which were treated with phenacyl bromides to obtain the corresponding S-phenacyl derivatives. The latter underwent base-catalyzed intramolecular cyclization with formation of 6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines spiro-fused to 2-oxo-2,3-dihydro-1H-indole fragment at C³. Analogous cyclization of 2,6-di-tert-butyl-4-[5-hetaryl-3-(2-aryl-2-oxoethylsulfanyl)-4H-1,2,4-triazole-4-ylimino]cyclohexa-2,5-dienones involved the imino nitrogen atom to produce the corresponding 6-aroyl-5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hetaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles.     

Reaction of methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2-carboxylates with arylhydrazines. synthesis of isomeric 5-arylcarbamoyl-4-aroyl- and 5-aryl-4-aryloxamoyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazoles

Methyl 3-aroyl-1-aryl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with arylhydrazines to give methyl 3-aroyl-1-aryl-2-(2-arylhydrazinyl)-4-hydroxy-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylates which underwent thermal recyclization into isomeric methyl 1-aryl-5-(arylcarbamoyl)-4-aroyl-1H-pyrazole- 3-carboxylates and methyl 1,5-diaryl-4-[2-oxo-2-(arylamino)acetyl]-1H-pyrazole-3-carboxylates.     

Synthesis of ethyl 2-[(1-aryl-1H-1,2,4-triazol-3-yl)oxy]propionates and related derivatives

Alkylation of 1-aryl-1H-1,2,4-triazol-3-ols with ethyl 2-bromopropionate under basic conditions resulted in the formation of 2-[(1-aryl-1H-1,2,4-triazol-3-yl)oxy]propionic acid, ethyl esters. No N-alkylated products were detected. Similar alkylation of 2-oxo-5-phenyl-1,3,4-thiazole and the corresponding 1,3,4-oxadiazole gave only N-alkylated derivatives. With 4-hydroxy-6-phenylpyrimidine and 2-oxo-4-phenylthiazole, both O- and N-alkylation occurred. Structure assignments were based on ir and ¹³C nmr spectral data.     

Ene Synthesis of Bicyclic Arylmethylenedihydropyrazoles Using 4-Phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione

8-Acetyl-7-aryl-2-arylmethylene-8,9-diaza- and 4,8,9-triazabicyclo[4.3.0]non-9-enes react with4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione, following the ene addition pattern. Under similar conditons 7-aryl-2-arylmethylene-8-methyl-8,9-diazabicyclo[4.3.0]non-9-enes give rise to both mono- and polyadditionproducts. The product structures were studied by ¹H and ¹³C NMR, IR, and UV spectroscopy and singlecrystal X-ray diffraction.     

Über die Synthese einiger Derivate des Pyrazolo [3,4-e]-1,2,4-triazins

Zusammenfassung Durch Kupplung von Diazoniumsalzen mit 3-Äthoxycarbonylamino-1-phenyl-5-pyrazolon wurden einige entsprechende Hydrazone (1) hergestellt. Durch thermische Cyclisierung wurden diese Substanzen glatt in 2-Aryl-6-phenyl-3,4,6,7-tetrahydro-2H-pyrazolo[3,4-e]1,2,4-triazin-3,7-dione bzw. in die 2,3,6,7-5H-Tetrahydrotautomeren (2) übergeführt.

---

Cyclization of hydrazones. III: Syntheses of some pyrazolo [3,4-e]-1,2,4-triazine derivatives

By coupling diazonium salts with 3-ethoxycarbonylamino-1-phenyl-5-pyrazolone a series of arylhydrazones (1) was prepared. These substances were thermally cyclized into 2H-2-aryl-6-phenyl-3,4,6,7-tetrahydropyrazolo[3,4-e]1,2,4-triazine-3,7-diones or into their corresponding 2,3,6,7-tetrahydro-5H-tautomers (2).