Synthesis, properties, and structures of ammonium 4-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates

The reaction of arylcyanomethylenethiocetamides with Meldrum, acid gave Michael adducts as ammonium salts. When heated in alcohol, these salts undergo cyclization to ammonium 4-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates. The structure ofN-methylmorpholinium 4-(2′-chlorophenyl)-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolate was established by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1029–1034, May, 1997.     

Synthesis of 4-aminoisoxazole-3-carboxamides using base-promoted nitrosation of N-substituted cyanoacetamides

The reactions of N-substituted cyanoacetamides with EtONO in the presence of an equimolar amount of EtONa afforded the corresponding sodium salts of hydroxyimino derivatives in 70—95% yields. The latter were transformed into 4-amino-5-(4-bromobenzoyl)isoxazole-3-carboxamides in 30—57% yields using the known method.     

Facile One-Pot,Multicomponent Synthesis of Pyridines Under Microwave Irradiation

A series of 2-amino-6-(2-oxo-2H-chromen-3-yl)-4-pyridine-3-carbo-nitriles were synthesized by the one-pot, multicomponent reaction of 3-acetyl-coumarin, aromatic aldehydes, malononitrile, and ammonium acetate in acetic acid under microwave irradiation. The reactions were completed in 10–13 min with 61–86% yields, were environmental benign, and had easy workup. Their structures were confirmed by ¹H NMR, IR, and MS spectra and elemental analysis.     

Synthesis of new functionally substituted fullerenopyrrolidines

New fullerenopyrrolidines were synthesized by the three-component reactions of fullerene C₆₀, N-methylglycine, and aromatic aldehydes, viz., N,N-bis(2-chloroethyl)-4-aminobenzaldehyde, N-(2-chloroethyl)-N-methyl-4-aminobenzaldehyde, indole-3-carbaldehyde, 4-phenylbenzaldehyde, and anthracene-9-carbaldehyde. The structures of the resulting compounds were established by spectroscopic methods.     

The Mannich reaction in the synthesis of N,S-containing heterocycles 8. Aminomethylation of 3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates as a method for the synthesis of new functionally substituted 3,7-diazabicyclo[3.3.1]nonane derivatives

Aminomethylation of 3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates upon treatment with primary amines and excess formaldehyde leads to 3,7-diazabicyclo[3.3.1]nonane derivatives. N-Methylmorpholinium 4-(2-chlorophenyl)-3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolate was obtained by the reaction of (E)-3-(2-chlorophenyl)-2-cyanoprop-2-enethioamide with 1-cyanoacetyl-3,5-dimethylpyrazole and N-methylmorpholine in acetone in quantitative yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2397–2400, December, 2007.     

Design,synthesis and antimicrobial activities of 1,2,3-triazole derivatives

Fifteen 1-(4-substituted phenyl)-4-(4-bromophenyl)-5-(halo-o-hydroxyphenyl)imino-1,2,3-triazoles were designed and synthesized based on rational combination of 1,2,3-triazoles and(halo)o-hydroxyphenyl group according to the superposition principle of reinforcement of biological activities.All the compounds were tested to an in vitro antimicrobial screening against M.a.and E.c..Compounds IIe-IIo exhibited more potent antimicrobial activities against M.a.and E.c.than triclosan and fluconazole,which provided valuable information to further study of novel antimicrobial research.     

A convenient synthesis of coumarin-3-carboxylic acids via Knoevenagel condensation of Meldrum's acid with ortho-hydroxyaryl aldehydes or ketones

Coumarin-3-carboxylic acids were obtained in high yields with excellent purity from ortho-hydroxybenzaldehydes and Meldrum's acid after a 2 h reflux in ethanol. The less reactive ketones were first reacted with alcoholic ammonia to form ketimines, which were then condensed with Meldrum's acid to generate 4-alkylcoumarin-3-carboxylic acids in moderate yields.     

3-Cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines in the synthesis of substituted 3-(aminomethyl)pyridines

The reactions of substituted 3-cyanopyridine-2(1H)-thiones and 3-cyano-2-(methylthio)pyridines with lithium aluminum hydride in anhydrous diethyl ether afforded the corresponding 3-aminomethyl derivatives, which were used in the synthesis of the corresponding amides.     

4-(3-Cyanopyridin-2-ylthio)acetoacetates in synthesis of heterocycles

Substituted 2-amino-4-aryl-3-cyano-5-oxo-5,6-dihydro-4H-pyrano[2,3-d]pyrido[3",2":4,5]thieno[3,2-b]pyridines were synthesized by the reactions of 4-hydroxy-1H-thieno[2,3-b;4,5-b]dipyridin-2-ones with arylidenemalononitriles or by the three-component reactions of hydroxythienodipyridinones with aldehydes and malononitrile in DMF in the presence of triethylamine. Methods for syntheses of substituted 3-alkoxycarbonyl-6-amino-4-aryl-2-(3-cyanopyridin-2-ylthiomethyl)-4H-pyrans were developed on the basis of the reactions of 4-(3-cyanopyridin-2-ylthio)acetoacetates and arylidenemalononitriles or aldehydes and malononitrile. Ethyl 4-(3-cyanopyridin-2-ylthio)acetoacetate and 4-methoxybenzylidenecyanothioacetamide were used for the synthesis of 6-(pyridin-2-ylthiomethyl)-3-cyanopyridine-2(1H)-thione.     

Claisen aromatic amino rearrangement in the series of fluorinated anilines

The effect ofmeta-substituents in the aromatic ring on the route of Claisen rearrangement ofN-(pent-3-en-2-yl)-3-fluoro(or 3-trifluoromethyl, 3,4-difluoro)anilines induced by ZnCl₂ was investigated. The formation of two possibleortho-alkenylated reaction products was observed. The ratio of these isomers depends on the nature of the acid catalyst. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 188–190, January, 1998.     

Unexpected synthesis of 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane

The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield.     

Synthesis ofN-substituted 2-(5,6,7,8-tetrafluoro-4-oxo-1,4-dihydroquinolin-3-yl)glyoxylic acids

Methods for the synthesis of the earlier unknownN-substituted 2-(5,6,7,8-tetrafluoro-4-oxo-1,4-dihydroquinolin-3-yl)glycoxylic acids their esters from copper chelate of ethyl pentafluorobenzoylpyruvate were developed. The structure of intermediate ethyl 4-(R-amino)-2-oxo-3-pentafluorobenzoylbut-3-enoates is discussed. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1234–1239, July, 2000.     

Synthesis of substituted 2-amino-1,3-thiazine-6-thiones

The reaction of thiourea with l-acyl-2-bromoacetylenes in AcOH in the presence of BF₃·Et₂O affords 2-amino-4-phenyl(2-thienyl)-1,3-thiazine-6-thiones in high yields. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 11, pp. 1947–1949, November, 2000.     

Reaction of vinyloxyalkylamines with mercaptoacetic acid

N-[2(3)-Hydroxyalkylj-4-thiazolidinones have been synthesized by the reaction of 2(3)-vinyloxyalkylamines with mercaptoacetic acid in 24–69 % yield. The structure of the compounds obtained was supported by (R and¹H NMR spectroscopic data.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 677–679, March, 1996.     

Unusual multi-component condensation in the synthesis of 1,4-dihydro-1,6-naphthyridine derivatives

Multi-component condensation of cyanoselenoacetamide with ethyl 2-furfuryl-idenacetoacetate and liquid alkyl halides, catalyzed byN-methylmorpholine, affords 7-alkylseleno-5-amino-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-2-methyl-1,4-dihydro-1,6-naphthyridines, which have not been described hitherto. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 121–124, January, 2000.     

Unusual multi-component condensation in the synthesis of 1,4-dihydro-1,6-naphthyridine derivatives

Multi-component condensation of cyanoselenoacetamide with ethyl 2-furfuryl-idenacetoacetate and liquid alkyl halides, catalyzed byN-methylmorpholine, affords 7-alkylseleno-5-amino-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-2-methyl-1,4-dihydro-1,6-naphthyridines, which have not been described hitherto. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 121–124, January, 2000.     

Novel Stereoselective Synthesis and Molecular and Crystalline Structure of 3-Allyl-4-(4-bromophenyl)-3-cyano-6-oxopiperidine-2-thione

The stereoselective synthesis of 3-allyl-4-(4-bromophenyl)-3-cyano-6-oxopiperidine-2-thione has been carried out by refluxing N-methylmorpholinium 5-[1-(4-bromophenyl)-2-cyano-2-thiocarbamoylethyl]-2,2-dimethyl-1,3-dioxa-6-oxo-4-cyclohexen-4-olate with allyl bromide in ethanol. The structure of the product was confirmed by X-ray investigation.     

Reactions with pyrrolidine-2,4-diones,II: New approaches to the synthesis of substituted 5,6-dihydropyrrolo[3,4-d][1,2,3]triazol-4(2H,4H)ones

Summary Approaches leading to 5,6-dihydro-5,6-diphenyl-2-substituted-pyrrolo[3,4-d][1,2,3]-triazol-4(2H,4H)-ones (10) are described. The first approach consists of cyclodehydrating 3(or 4)-hydroxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (4,7) with boiling acetic anhydride. The second approach involves cyclization of 3(or 4)-acetoxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (8,9) with elimination of acetic acid upon treatment with sodium hydroxide.Part of the work has been presented at the 8^th International Congress of Heterocyclic Chemistry (August 1981), Graz, Austria