Unexpected formation of 4-aryl-3-cyano-6-phenylpyridine-2(1H-thiones from the reaction of arylmethylenecyanothioacetamides with benzoyl-1,1,1-trifluoroacetone

4-Aryl-3-cyano-6-phenylpyridine-2(1H)-thiones, used in the synthesis of substituted 2-alkylthiopyridines, thieno[2,3-b]pyridines, and 1,4-di(pyridin-2-ylthio)butane, have been synthesized by the condensation of arylmethylenecyanothioacetamides with benzoyl-1,1,1-trifluoroacetone. The reaction path includes the formation of the Michael adduct which undergoes loss of the acyl group. The structure of 3-cyano-2-methylthio-4-(1-naphthyl)-6-phenylpyridine has been studied by X-ray crystallography. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, 1821–1828, December 2005.     

Synthesis, Structure, and Some Properties of Substituted 3-Carbethoxy(methoxy)-5-cyano-1,2,3,4-tetrahydrospirocyclohexane-4-pyridine-2-thiones

The condensation of cyclohexylidenemalononitrile or cyclohexylidenecyanoacetic ester with thioamidoethyl(methyl)malonate in the presence of sodium ethylate gave 6-amino-3-carbethoxy-5-cyano-4-spirocyclohexane-1,2,3,4-tetrahydropyridine-2-thione and 3-carbethoxy(methoxy)-5-cyano-6-oxo-4-spirocyclohexanepiperidine-2-thiones which were used in the synthesis of the corresponding substituted 2-alkylthiotetrahydropyridines. 5-Carbethoxy-3-cyano-3-methyl-6-methylthio-4-spiro-cyclohexane-3,4-dihydropyridine-2(1H)-one was studied by X-ray crystallography.     

Synthesis of 6-substituted 3-cyano-5-nitropyridine-2(1H)-thiones

The reactions of 1-substituted 2-nitro-3-phenylaminoprop-2-en-1-ones with cyanothioacetamide afforded the corresponding 6-substituted 3-cyano-5-nitropyridine-2(1H)-thiones, which were used for the synthesis of 6-substituted 3-cyano-2-methylthio-5-nitropyridines and 7-substituted 4-hydroxy-8-nitropyrido[2",3":4,5]thieno[2,3-b]pyridin-2(1H)-ones.     

Hetarylnitrenes V. Reactions of Tetrazolopyrazine Ring Contraction of Nitrenodiazines in Solution. Preliminary communication

Thermolysis of tetrazolopyrazine ( 1 ) in organic solvents gives pyrazinylnitrene ( 2 ) which undergoes ring contraction to 1-cyanoimidazole ( 3 ). 7-Methyl-5-methylthio-tetrazolo[1,5-c]pyrimidine ( 4 ) likewise gives 1-cyano-2-methylthio-4-methyl-imidazole ( 6 ). The two tetrazoles also undergo ring contraction to 1-cyanoimidazoles by gas chromatography, and 1 gives a low yield of 3 by photolysis. Thermolysis of 1 and 4 in cyclohexane gives aminopyrazine ( 7 ) and 6-amino-4-methyl-2-methylthio-pyrimidine ( 8 ), respectively. Tetrazolo[1,5-a]pyrimidines ( 9 ) give only 2-aminopyrimidines ( 10 ). 1-Cyanoimidazole, formed by thermolysis of 1 in acetic acid, reacts further to give 1-acetylimidazole, which with more acetic acid gives imidazole and acetic anhydride. An earlier report [2] of ring expansion of pyrazinylnitrene in acetic acid is discredited. In protic deuteriated solvents (D₃O, CH₃OD), tetrazolopyrazine reacts as an enamine, specifically exchanging H? C(6) for deuterium.     

Synthesis of N-methylmorpholinium 6-oxo-3,5-dicyano-1,4,5,6-tetrahydro-4-(spirocyclopentane)pyridine-2-thiolate with the Michael reaction

N-Methylmorpholinium 6-oxo-3,5-dicyano-1,4,5,6-tetrahydro-4-(spirocyclopentane)pyridine-2-thiolate was obtained by reaction of cyclopentylidenecyanoacetic ester with cyanothioacetamide or cyclopentylidenecyanothioacetamide with cyanoacetic ester in the presence of N-methylmorpholine; it is used in synthesis of substituted 2-alkylthiotetrahydropyridines, 5-oxo-6,8-dicyano-2,3,6,7-tetrahydro-(5H)-7-(spirocyclopentane)-thiazolo[3,2-a]pyridine, 5-allyl-2-methylthio-3,5-dicyano-4,5-dihydro-4-(spirocyclo-pentane)pyridin-6(1H)-one, and 3-amino-6-oxo-5-cyano-4,5-dihydro-4-(spirocyclopentane)-2H-pyrazolo[5,4-b]pyridin-6(7H)-one. T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011, Ukraine, N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 208–212, February, 1998.     

Novel Approaches to Synthesis of 4-Alkyl-6-amino-5-cyano-3-methyl(propyl, phenyl)-2H,4H-pyrano[2,3-c]pyrazoles

We have obtained 4-alkyl-6-amino-5-cyano-3-methyl(propyl, phenyl)-2H,4H-pyrano[2,3-c]pyrazoles by reaction of 4-alkylmethylene-3-substituted 5-pyrazolones with malononitrile or cyanothioacetamide. We have used X-ray diffraction to study the structure of 6-amino-5-cyano-4-isopropyl(hexyl)-3-phenyl-2H,4H-pyrano[2,3-c]pyrazoles.     

Synthesis, Structure and Biological Activities of 2-Methylthio-3-cyano-7-（4-methoxyphenyl）- pyrazolo[1,5-a]pyrimidine

1INTRODUCTION Pyrazolo[1,5-a]pyrimidine derivatives have shown various biological activities in the terms of antibac-terial,antischistosomal and xanthine oxidase inhibi-tors[1~5].The enaminones are highly reactive inter-mediates and have been extensively used as build-ing blocks in organic synthesis especially in the he-terocyclic compounds[6~8].In addition,a great deal of interest has been focused on the synthesis of py-razolo[1,5-a]pyrimidine through versatile enamino-nes because of thei…     

Cyclization reactions of nitrils. 29. Regioselective synthesis of 6-aryl-3-cyano-2(1H)-pyridinethiones and the corresponding selenones and their characteristics

The condensation of cyanothio- and cyanoselenoacetamide with 3-aryl-3-oxo-1-piperidino-1-propene or sodium 3-aryl-3-oxo-1-propen-1-olate takes place regioselectively with the formation of the 6-aryl-3-cyano-2(1H)-pyridinethiones or the corresponding selenones. Thieno[2,3-b]pyridines, thiazolo[3,2-a]pyridinium salts, and other annellated heterocycles were obtained from the 6-aryl-3-cyano-2(1H)-pyridinethiones.For Communication 28, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 805–812, June, 1988.     

Preparation and properties of piperidine salts of 6-hydroxy-4,6-diaryl-5-ethoxycarbonyl-3-cyanopiperidine-2-thiones

Alkylation of piperidine salts of 6-hydroxy-4,6-diaryl-5-ethoxycarbonyl-3-cyanopiperidine-2(1H)-thiones yielded 6-hydroxy-2-alkylthio-4,6-diaryl-5-ethoxycarbonyl-3-cyano-3,4,5,6-tetrahydropyridines which were dehydrogenated with the formation of 2-methylthio-1,4- and 4,5-dihydropyridines. The oxidation of the compounds prepared has been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–80, January, 1987.     

Über die Umlagerung von Benzo[b]-1, 4-thiazepinen und 1, 4-Thiazepinen

The rearrangement of differently substituted 1, 4-thiazepines under various reaction conditions has been investigated. 2-Phenyl-4-methylthio-benzo [b]-1, 4-thiazepine ( 3 ) and 2-phenyl-benzo [b]-1, 4-thiazepine-4 (5H)-thione ( 2 ) extrude sulfur under the catalytic influence of bases and rearrange into 2-methylthio-4-phenyl-quinoline ( 4 ) and 4-phenyl-thiocarbostyril ( 6 ) respectively. Under the same conditions, 2-phenyl-4-methylthio-2, 3-dihydro-benzo [b]-1, 4-thiazepine ( 11 ) rearranges to 2-styryl-benzothiazine ( 12 ), whereas the dioxide 18 shows no tendency to rearrange. 2,7-Diphenyl-hexahydro-1,4-thiazepine-5-one( 19 ) could be converted into 2-styryl-5-phenyl-2-thiazoline ( 20 ) by treatment with polyphosphoric acid. The possible mechanisms of these rearrangements are discussed.     

One-Pot synthesis of N-heterocyclic compounds from cyclopropenethione derivatives

The one-pot reaction of 2-tert-butylthio-3-phenylcyclopropenethione (1a) and its 3-(2-thienyl) derivative (1b) with lithium pyrrolidinide at -70 degrees C, followed by methylation with methyl iodide, gives 6-methylthio-5-phenyl-2,3-dihydro-1H-pyrrolizine (2a) and its 5-(2-thienyl) derivative (2b), respectively. The reaction of 2-tert-butylthio-3-(pyrrolidin-1-yl)cyclopropenethione (1c) with phenyllithium gives also 2a in a high yield under similar conditions, and the reactions of 1a with N-lithium salts of 3-pyrroline, hexamethyleneimine, indoline, and carbazole, piperidine-potassium tert-butoxide mixture, and phenyllithium give 6-methylthio-5-phenyl-3H-pyrrolizine (3), 2-methylthio-3-phenyl-6,7, 8,9-tetrahydro-5H-pyrrolo[1,2-a]azepine (5), 6-tert-butylthio-5-methylthio-4-phenyl-1,2-dihydro-6H-pyrrolo[3,2, 1-ij]quinoline (6), 4-tert-butylthio-5-methylthio-6-phenyl-4H-pyrido[3,2,1-jk]carbazole (7), 2-methylthio-3-phenyl-5,6,7,8-tetrahydroindolizine (4), and 1-tert-butylthio-2-methylthio-3-phenylindene (9), respectively. The structures of 2a and 3 were determined by X-ray analyses of their tricarbonylchromium complexes.     

Sequential approach to the synthesis of 'U and Z' shaped polycyclic heteroarenes

The synthesis of three new classes of heteroarenes, built through the sequential fusion of naphthalene, benzo/naphtho[b]oxepine and thiochromene rings with pyran and pyrimidine ring systems to give 'U and Z' shaped structural frameworks is reported. The methodology is based on the synthesis of pyran fused intermediates, 1-methylthio-3-oxo-5,6-dihydro-3H-benzo[f]chromene-2-carbonitrile (3), 4-methylthio-2-oxo-5,6-dihydro-2H-benzo/naphtho[b]pyrano[2,3-d]oxepine-3-carbonitriles (10, 20) and 4-methylthio-2-oxo-2,5-dihydrothiochromeno[4,3-b]pyran-3-carbonitriles (15) from the reaction of 2-tetralone, benzo/naphtho[b]oxepin-5-ones and thiochromen-4-ones with methyl 2-cyano-3,3-dimethylthioacrylate respectively. Further condensation of intermediates 3, 10, 20 and 15 with amidines led to the formation of tetracyclic 'U' shaped 4-amino-2-aryl-7,8-dihydro-5-oxo-5H-naphtho[2,1-b]pyrimido[4,5-d]pyrans (8) and 'Z' shaped 4-amino-2-aryl-5-oxo-12,13-dihydro-5H-benzo/naphtho[b]oxepino[5,4-b]pyrimido[4,5-d]pyrans (12, 22) and 4-amino-2-aryl-5-oxo-5,12-dihydrothiochromeno[4,3-b]pyrimido[4,5-d]pyrans (17). Compound 12f forms a chain of dimers through N-HO interactions as indicated by the X-ray structure analysis, and the quantum chemical calculations performed at the MP2 level indicate that this interaction energy is 10 kJ mol(-1).     

Cyclisierung von 3-Acylmethylthio-4-cyan-2H-isothiazol-5-thionen

The title compounds2 cyclize on mild conditions to the intermediate 7-cyano-thiazolo[3,2-b]isothiazole-6-thiones3 which are converted immediately into the 1,2,4-trithiolane-3,5-diylidene-(thiazole-2-yl)-acetonitriles4 accompanied by extrusion of sulphur. The cyclization of the 4-cyano-5-methylthio-3-phenacylthio-isothiazole (6) yields the 7-cyano-6-methylthio-thiazolo[3,2-b] isothiazoliumsalt7 which undergoes reductive ring opening by hydrazine hydrate to yield methyl (4-phenyl-thiazolin-2-ylidene)-cyanodithioacetate (8).     

5-Cyano-6-aryluracil and 2-thiouracil derivatives as potential chemotherapeutic agents. IV

A series of 5-cyano-6-aryluracils and 2-thiouracils 1a-h has been prepared and alkylated to 1,3-dialkyluracils 2a-d and 2-alkylthiouracils, 3, 4 and 6 , by electrophilic substitution with alkyl halides. Reaction of 1b with dibromoethane and 1,3-dibromopropane gave the corresponding bicyclic products, 7-aryl-6-cyano-2,3-dihydrothiazolo[3,2-a]pyrimidin-5-ones 5a,b and 8-aryl-7-cyano-3,4-dihydro-2H-pyrimido[2,3-b][1,3]thiazin-6-ones 5c-g . Nucleophilic substitution on 6 with hydrazine led to 7 which on refluxing with formic acid gave 5-aryl-6-cyano-8-methyl-s-triazolo[3,4-b]pyrimidin-7-ones ( 9 ), while with acetic and propionic acids only 2-acylhydrazino-3-methyl-4-oxo-5-cyano-6-arylpyrimidines 8a,b were isolated. The hydrazine 7 undergoes cyclization with acetylacetone and methyl dimethylmercaptoacrylate providing 2-(pyrazol-1-yl)-3-methyl-4-oxo-5-cyano-6-substituted pyrimidines 10 , and 11 . Some of the compounds were screened for antibacterial-, antifungal- and antiviral activities and a few of them showed significant chemotherapeutical activities.     

Synthesis of 8-amino-4-methylthio-6-methyl-2-(β-D-ribofuranosyl)-2,6-dihydro-1,2,3,5,6,7-hexaazaacenaphthylene and an unusual reductive ring-opening of the 1,2,3,5,6,7-hexaazaacenaphthylene ring system

The tricyclic nucleoside 8-amino-4-methylthio-6-methyl-2-(β-D-ribofuranosyl)-1,2,3,5,6,7-hexaazaacenaphthylene ( 3 ) was synthesized from 3-cyano-4,6-bis(methylthio)-1-(β-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine ( 1 ). Attempts to synthesize 8-amino-6-methyl-2-(β-D-ribofuranosyl)-1H-2,6-dihydro-1,2,3,5,6,7-hexaazaacenaphthylene ( 5 ) ([an aza analog of 6-amino-4-methyl-8-(β-D-ribofuranosyl)-1,3,4,5,8-pentaazaacenaphthylene (TCN)], which is a potent antitumor agent), by the treatment of 3 with Raney nickel did not afford the desired aza analog of TCN. Instead, it was established that a reductive cleavage of the pyridazine moiety of 3 had occurred to give 4-methylamino-6-methylthio-1-(β-D-ribofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboxamidine ( 6 ). Assuming that solubility was a problem in the reductive step, the isopropylidene derivative of 3 , 8-amino-6-methyl-4-methylthio-2-(2,3-O-isopropylidene-β-D-ribofuranosyl)-2,6-dihydro-1,2,3,5,6,7-hexaazaacenaphthylene ( 8 ), was treated with Raney nickel, only to observe that a similar reductive ring cleavage of 8 had occurred to afford 4-methylamino-6-methylthio-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboxamidine ( 10 ) and 4-methylamino-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboxamidine ( 11 ). Structural assignments for all products were established by physico-chemical procedures.     

Propanal in the Syntheses of Alkyl-substituted 3-Cyano-2-piperidone, 3-Cyano-2,5,6,7-tetrahydropyrindin-2(1H)-one, and 3-Cyanopyridine-2(1H)-thione

Condensation of propanal with cyanothioacetamide and morpholine gave 3-cyano-4-ethyl-5-methyl-6-morpholino-2-piperidone, the structure of which was studied by X-ray analysis. Reaction of propanal with cyanothioacetamides and cycloalkanone enamines gave 3-cyano-4-ethyl-2,5,6,7-tetrahydropyrindin-2(1H)-one and 3-cyano-4-ethyl-5,6-hexamethylenepyridine-2(1H)-thione. The latter was used for the preparation of substituted 2-benzyloxycarbonylmethylthiopyridine and 3-amino-2-benzyloxycarbonylthieno[2,3-b]pyridine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1053–1059, July, 2005.     

Reaction of Ketene Dithioacetals with Pyrazolylcarbohydrazide:Synthesis and Biological Activities of Ethyl 5-Amino-1-(5''''- methyl-1''''-t-butyl-4''''-pyrazolyl)carbonyl-3-methylthio-1H-pyrazole-4-carboxylate

Introduction Pyrazole and its derivatives represent one of the most active classes of compounds possessing a wide spectrum of biological activities. During the past years, considerable evidence has been accumulated to demon-strate the efficacy of pyrazole derivatives including an-tibacterial,1 antifungal,2 herbicidal,3 insecticidal4 and other biological activities.5-7 Up to now, a great variety of these kind of compounds have been synthesized, among which some commercially pesticides have been…     

New data on the alkylation of cyclic thioureas with á-halocarboxylic acids and their esters. 2. Alkylation of tetrahydropyrimidine-2(1h)-thione and 5,5-dimethyltetrahydropyrimidine-2(1h)-thione

In the absence of bases all the attempted variations for the alkylation of tetrahydropyrimidine-2(1H)-thione with á-halocarboxylic acids gave only the bicyclic product-2-R-6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidin-3(2H)-one hydrohalide. However the hydrohalide of the “ open” S-ethoxycarbonyl derivative of propyleneisothiourea can be obtained by treatment of tetrahydropyrimidine-2(1H)-thione with ethyl chloro-or bromoacetate in anhydrous acetone at room temperature. Alkylation of 5,5-dimethyltetrahydro-2(1H)-pyrimidinethione with chloro-or bromoacetic acid in anhydrous acetone at room temperature gave the hydrohalide of the “open” S-carboxymethyl derivative of dimethylpropyleneisothiourea. All remaining variations for the alkylation of this substrate with á-halocarboxylic acids or their esters gave only the corresponding bicyclic compounds-the hydrohalide of 2-R-6,6-dimethyl-6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidin-3(2H)-one-independently of the reaction conditions. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 593–604, April, 2006.     

Synthesis of methyl esters of 5-amino-4-(substituted amino)-2-methylthio-7H-pyrrolo[2,3d]-pyrimidine-6-carboxylic acids

The optimum route for the synthesis of methyl esters of N-[(4-substituted amino)-5-cyano-2-methylthiopyrimidin-6-yl]amino acids (which are starting materials for preparing the methyl esters of the corresponding 5-amino-4-(substituted amino)pyrrolo[2,3-d]pyrimidine-6-carboxylic acids) is via subsequent reactions of 4,6-dichloro-2-methylthiopyrimidine-5-carbonitrile with amines and methyl glycinate. In some examples, the reaction of methyl N-(4-chloro-2-methylthio-6-pyrimidinyl)aminoacetate with amines occurs to give the corresponding acid amides. The previously unknown synthesized derivatives of pyrimidin-6-yl amino acids and 4,5-diaminopyrrolo[2,3-d]pyrimidine- 6-carboxylic acids possess fungicidal properties.Vilnius University, Vilnius 2006, Lithuania. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 7, pp. 955–961, July, 2000.     

Electrochemical synthesis and studies of substituted 2-thiopyridines

A series of substituted 2-alkyl(aryl-, hetaryl-)thiopyridines was prepared by cathodic electrolysis of thiols in the presence of 2-chloro-3-cyano-4-methoxymethyl-6-methylpyridine or 4-chloro-6-methyl-3-oxo-1H-furo[3,4-c]pyridine. The reaction of 3-cyano-4-methoxymethyl-6-methyl-2(1H)-thiopyridone with alkyl halides in the presence of KOH is regioselective and leads toS-alkyl derivatives. The advantages of electrosynthesis for the preparation of 2-alkylthiopyridines fused with 2(5H)-furanone and of 3-aminothieno [2,3-b]pyridines is demonstrated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2215–2219, December, 1994.