Synthesis of 2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine and its 1-α-L-arabinopyranoside

A new type of isatin analog-2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine — was obtained by oxidation of 4-methyl-6-chloro-1H-pyrrolo(2,3-b]pyridine. Condensation of L-arabinose with 4-methyl-6-chloro-2,3-dihydropyrrolo[2,3-b]pyridine and subsequent acetylation and dehydrogenation gave 1-(2,3,4-tri-O-acetyl--L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine, which served as the starting compound for the synthesis of 1--L-arabinopyranosyl-4-methyl-6-chloropyrrolo[2,3-b]pyridine. Oxidation of 1-(2,3,4-tri-O-acetyl-L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine gave 1-(2,3.4-tri-O-acetyl--L-arabinopyranosyl)-2,3-dioxo-2,3-dihydro-4-methyl-6-chloropyrrolo [2,3-b]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1083–1086, August, 1977.     

Synthesis and structure of novel derivatives of thieno[2,3-b]thiocine. An unusual product of intramolecular cycloaddition of 2-homomethallylthio-5-methyl-3-thiophenecarbonitrile oxide

9-Methyl-3,3a,4,5-tetrahydro-6H-thieno[2,3-b]thiocino[4,5-c]isoxazole and 9-hydroxyimino-2-methyl-7-methylene-6, 7,8,9-tetrahydro-5H-thieno[2,3-b]thiocine have been prepared for the first time by the oxidation of 2--alkenylthio-3-thiophenecarbaldoximes with NaOCl. X-ray structural investigations of thieno[2,3-b]thiocine and 2-homomethallylthio-5-methyl-3-thiophenecarbaldoxime have been carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1262–1266, July, 1993.     

Cyclization of n-alkylazinium cations with bisnucleophiles. 4. Regio- and stereospecificity of the reactions of β-diketones with quinoxalinium salts and their aza and benzo analogs

The reactions of substituted quinoxalinium, benzo[g]- and benzo[f]quinoxalinium, and pyrido[2,3-b]pyrazinium salts with anions of -dicarbonyl compounds give furo[2,3-b]-annelated systems with strictly determined regio- and stereoorientations.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1543–1548, November, 1981.     

Thermal transformations of allyl 2-thienyl sulfide and selenide

In the gas phase at 350–410C allyl 2-thienyl sulfide is converted to thiophene-2-thiol, di(2-thienyl) sulfide, and 2-methylthieno[2,3-b]thiophene. In the presence of acetylene thieno[2,3-b]thiophene is formed in addition to these products. Allyl 2-thienyl selenide is converted quantitatively to 2,3-dihydro-2-methylselenopheno[2,3-b]thiophene during fractional distillation in vacuo. Thiophene, di(2-thienyl) selenide, di(2-thienyl) diselenide, thiophene-2-selenol, and 2-methylselenopheno[2,3-b]thiophene are formed in addition to these compounds in the thermolysis of allyl thienyl selenide in the gas phase. In the presence of acetylene the thermal decomposition of allyl thienyl selenide is accompanied by the formation of selenophene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1316, October, 1991.     

Novel One-Pot Multicomponent Synthesis of Substituted 2,3-Dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones and Substituted 3-[3-(N′-Benzylidene-hydrazino)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones

A one-pot procedure has been developed for the synthesis of substituted 2,3-dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones by reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and phthalic anhydrides in acetic acid medium. Similarly, a one-pot, three-component synthetic procedure has been developed for substituted 3-[3-(N¹-benzylidene-hydrazino)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones from 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and various aromatic aldehydes in absolute ethanol and a few drops of glacial acetic acid.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis and properties of (thieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridin-3-yl)iminotriphenylphosphoranes. Molecular structure of (2-benzoyl-4-methoxymethyl-6-methylthieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridin-3-yl)iminotriphenylphosphorane

Iminophosphoranes containing a thieno[2,3-b]pyridine fragment were obtained through a sequence of reactions: 1) alkylation of 3-cyano-2(1H)-pyridinethiones in alkaline medium by an -halocarbonyl compound with subsequent Thorpe-Ziegler cyclization of the resultant 2-thioalkylpyridines to give 3-aminothieno[2,3-b]pyridines, 2) diazotization of the amino group and nucleophilic substitution of the diazonium group by an azido group without isolation of the diazonium salts, and 3) reaction of the 3-azidothieno[2,3-b]pyridines with triphenylphosphine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1853–1862, December, 2004.     

Studien zur Chemie von thienoanellierten O,N-und S,N-haltigen Heterocyclen, 5. Mitt.: Ein Zugang zum Thieno[2,3-b][1,4]oxazin-Ringsystem

Summary The reactivity of 5-acetyl-2-chloro-3-nitrothiophene with -hydroxyesters is described. The influence of the solvent (DMF, tetrahydrofurane, toluene) and of the used base is discussed. These reactions provide an access to substituted thiophene derivatives, which were cyclized after reduction by iron powder/glacial acetic acid to give thieno [2,3-b][1,4]oxazine derivatives.

     

Synthesis of condensed structures from 3-cyano-2-pyridylacrylic acids

Ammonolysis of the methyl esters of trans--(3-cyano-2-pyridyl)acrylic (I) and trans--(6-methyl-3-cyano-2-pyridyl)acrylic (II) acids gave the amides of these acids. The addition of bromine, diazomethane, and hydrogen to the double bond of cis- and trans-acids I and II is described. Hydrogenation of the methyl esters of trans-acids I and II over Raneynickel at room temperature and atmospheric pressure occurs with intramolecular cyclization to two-ring lactams — 7-oxo-5, 6,8,9-tetrahydropyrid[3,2-c]azepine and 2-methyl-7-oxo-5,6,8,9-tetrahydropyrid[3,2-c]azepine. Under the conditons of acid hydrolysis of acids I and II the elements of water add to the nitrile group with intramolecular cyclization to give, respectively, 3-carboxymethyl-1-oxo-2,3-dihydrofuro [4,3-b]pyridine and 5-methyl-3-carboxymethyl-1-oxo-2,3-dihydrofuro[4,3-b]pyridine, whereas refluxing these acids with aqueous sodium hydroxide gives two-ring lactams — 3-carboxymethyl-1-oxo-2, 3-dihydropyrrolo[4,3-b]pyridine and its 5-methyl homolog. The structures of the compounds were confirmed by the UV, IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 63–69, January, 1978.     

Synthesis and transformations of 2-(2-furyl)-and 2-[β-(2-furyl)vinyl]imidazo[4,5-b]phenazines

The corresponding 2-(2-furyl)- and 2-[-(2-furyl)vinyl]imidazo[4,5-b]phenazines were obtained by the condensation of 2,3-diaminophenazine with furfural and 2-furylacrolein and with their 5-bromo and 5-nitro derivatives. The phenazines were also synthesized by the reaction of 2-methylimidazo[4,5-b]phenazine with furfural and 5-bromo- and 5-nitrofurfural. The alkylation, acetylation, and nitration of the compounds obtained, as well as replacement of the halogen in the furan ring by a nitro group, were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1425–1428, October, 1971.     

Synthesis of 2-acylmethyl- and 2-acylmethylene-1,3-dithiolo[4,5-b]quinoxalines from α-acetylenic ketones

A number of 2-acylmethyl-1,3-dithiolo[4,5-b]quinoxaline derivatives were synthesized on the basis of the reaction of -acetylenic ketones with quinoxaline-2,3-dithiol in dimethyl sulfoxide (DMSO) in the presence of K₂CO₃. Their monohydrochlorides were obtained. A new series of 2-acylmethylene-1,3-dithiolo[4,5-b]quinoxalines was obtained by the reaction of 1-bromo-2-acylacetylenes with quinoxaline-2,3-dithiol in DMSO in the presence of triethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1489–1491, November, 1982.     

Synthesis and properties of hydrogenated 2-alkylthio-5-oxo-3-cyanoindeno [1,2-b]-pyridines

Condensation of 2-arylidene-1, 3-indandiones with cyanothioacetamide in the presence of piperidine, followed by treatment with alkyl halides, has given partially hydrogenated 2-alkylthio-5-oxoindeno [1,2-b]-pyridines, the oxidation, interconversion, and Thorpe cyclization of which to give a novel heterocyclic system, indeno [1,2:6,5] pyrido [2,3-b] thiophene, have been examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 115–119, January, 1990.     

Ring closure reactions of pyrido[2,3‐d]pyrimidines to pyrano[2′,3′:4,5]‐ and oxazolo[5′,4′:4,5]pyrido[2,3‐d]pyrimidines

The cyclocondensation of 5‐hydroxy‐pyrido[2,3‐d]pyrimidines 1 with malonates gives pyrano[2′,3′:4,5]‐pyrido[2,3‐d]pyrimidines 2 . Nitration of 1 and reduction with zinc in the presence of carboxylic acids/anhydrides gave 2‐alkyloxazolo[5′,4′:4,5]pyrido[2,3‐d]pyrimidines 4 , which were ring‐opened to 6‐aminopyrido[2,3‐d]pyrimidines 5, 6 and 7 . Cyclization of 6‐aminopyrido[2,3‐d]pyrimidines 6 with benzoylchlorides 8 gave 2‐aryloxazolo[5′,4′:4,5]pyrido[2,3‐d]pyrimidines 9 . Reaction conditions for the cyclization have been studied by differential scanning calorimetry (DSC).     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of o-aminomercapto derivatives of pyrimidine, pyrazine, and pyridine, with -halo acid nitriles was investigated. The corresponding cyanoalkylthio heterocycles, which were converted to 6-amino derivatives of pyrimido[4,5-b]-, pyrazino[2,3-b]-, and pyrido-[2,3-b]-1,4-thiazines, were obtained. The structures of the substances obtained were confirmed by IR, UV, and PMR spectroscopy.See [10] for communication XXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 944–948, July, 1972.     

A Useful Synthesis of 2-Methyl-2,3-dihydrofuro [2,3-b] Quinolines

A convenient, general synthesis of 2-methyl-2,3-dihydrofuro [2,3-b] quinolines is described from o-nitrobenzaldehydes. The benzaldehydes (la-c) on reaction with phosphorane 2 provide (E)-ethyl-α-allylcinnamates (3a-c) in high yields. These esters 3a-c on reduction followed by acid catalysed cyclisation give 2,3-dihydrofuro [2,3-b] quinolines (5a-c).     

Reaction of aromatic o-diamines with isatins. 2. 2,3-diaminonaphthalene

The reaction of 2,3-diaminonaphthalene with isatins gives a mixture of indolo[2, 3-b]benzo[g]quinoxalines, 3-(2-aminophenyl)-2(1H)-benzo[g]quinoxalines, and spiro (2,3-d]imidazoline)-2,3-indolin-2ones. The ratio between the products is influenced by the solvent and the relative value of the positive charge on the -carbon atom in the isatin.For report 1 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1399–1403, October, 1984.     

Nucleophilic substitution reactions in 2-chloropyridines and 2,5-dioxo-1,2,5,7-tetrahydro-1H-furo[3,4-b]pyridines

3-Cyano- and 3-carbamoyl-2-chloropyridines react with hydrazine hydrate to form substituted 3-amino-1H-pyrazolo[3,4-b]pyridines and 3-oxo-2,3-dihydro-1H-pyrazolo[3,4-b]pyridines. Hydrazine hydrate reacts with 3-carbamoyl-2-chloro-5-oxo-5,7-dihydrofuro[3,4-b]pyridine to form substituted 3,5-dioxo-2,3,5,7-tetrahydro-1H-pyrazolo[3,4-b]furo[3,4-e]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1218–1222, September, 1992.     

Spiro epoxy ketones. 2. Thermal transformations of 2-benzylideneindan-1,3-dioneα-oxide

2-Phenyl-3,3,4,4-diphthaloyloxetane is formed when solutions of 2-benzylideneindan-1,3-dione -oxide in benzene or carbon tetrachloride are heated, while 5-oxo-3-phenyl-2,2-phthaloyl-2,3-dihydroindeno[2,3-b][1,4]dioxine is formed when solutions in dioxane are heated.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 881–884, July, 1988.     

Condensed imidazo-1,2,4-azines. 21. Synthesis of 2-arylfuro(pyrrolo-, thieno-)[2,3-e]-1,2,4-triazino[2,3-a]benzimidazoles by cyclization of 2-aroyl-1,2,4-triazino[2,3-a]benzimidazol-4H-3-ones

2-[(-Ethyl-, arylimino)phenethyl]-1,2,4-triazino[2,3-a]benzimidazoles were obtained by reaction of 2-aroylmethyl-1,2,4-triazino[2,3-a]benzimidazol-4H-3-ones with ethyl(aryl)amines or urea. By the action of phosphorus oxychloride, these benzimidazoles cyclize into substituted pyrrolo[2,3-e]-1,2,4-triazino[2,3-a]benzimidazoles, heating of which in polyphosphoric acid leads to the formation of furo[2,3-e]-1,2,4-triazino[2,3-a]benzimidazoles, while by the action of P₄S₁₀, they are transformed into thieno[2,3-e]-1,2,4-triazino[2,3-a]benzimidazoles.For Communication 20, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1109–1113, August, 1989.     

Research on lactams

2-OxO-3,3-dihydroxy-4-bromohexahydroazepine was obtained by bromination of an enamine of -oxocaprolactam and subsequent hydrolysis of the resulting bromoimmonium salt and by direct bromination of -oxocaprolactam. The reaction of the product with thiourea, N-substituted o-aminothiophenols, aminouracils, and acetoacetic ester gave derivatives of thiazolo[4,5-c] azepine, azepino[4,3-b][1,4]benzothiazine, azepino [3,4-b]pyrrolo [2,3-d] pyrimidine, and furo[2,3-c] azepine.See [1] for communication XXVIII.Translated from Khimiya Geterotsiklicheskikh Soedlnenii, No. 3, pp. 374–378, March, 1978.     

(HET) Arylation of substituted acetonitriles. 1. Synthesis of 2-amino-3-(benzimidazol-2-yl)pyrrolo [2,3,b]-quinoxalines

It was shown that hetarylation of benzimidazol-2-ylacetonitriles by 2,3-dichloro-quinoxaline proceeds at the methylene group. The reaction of 2-chloro-3-[-cyano--(benzimidazol-2-yl) methylene]-3,4-dihydroquinoxalines formed with primary amines leads to 1-R-2-amino-3-(benzimidazol-2-yl)pyrrolo [2,3-b] quinoxalines.Translated from Khimiya Geterotsikli-cheskikh Soedinenii, No. 8, pp. 1119–1123, August, 1988.