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A series of new methyl 4-aryl-6-oxo-5-cyano-1,6-dihydropyridine-2-carboxylates and 4-aryl-6-oxo-5-cyano-1,6-dihydropyridine-2-carboxylic acids were synthesized by reacting methyl esters of acylpyruvic acids with malononitrile and cyanoacetamide, respectively.

The reaction of 1-(2-oxocyclohexyl)ethane-1,1,2,2-tetracarbonitrile with crotonic aldehyde, cinnamic aldehyde, 2-furylacrolein, 3-phenyl-2-propinal, 3-butyl-2-propinal, and R-(−)-myrtenal have been investigated. It has been shown that these reactions proceed through the stage of the formation of 8a-hydroxyhexahydro-2H-chromene-3,3,4,4-tetracarbonitrile, followed by the formation of 10-iminotetrahydro-8a,4-(epoxymethane)chromene-3,3,4(2H,4aH-tricarboritrile. The X-ray diffraction data have suggested that the stereochemical features of the target products are determined by the reaction path.

We discovered a new method to methylate tertiary amines such as urotropine, triethylamine, pyridine, 2-methylpyridine, 4-acetylpyridine, and isonicotinamide, up to quaternary ammonium compounds, with 1,1-dicyano-2-methoxy-2-oxoethane-1-ide being the counterion. Methyl-1,3,5,7-tetraazaadamantan-1-ium 1,1-dicyano-2-methoxy-2-oxoethane-1-ide, N,N-diethyl-N-methylethanaminium 1,1-dicyano-2-methoxy-2-oxoethane-1-ide, and substituted-methylpyridinium 1,1-dicyano-2-methoxy-2-oxoethane-1-ides were synthesized. Quaternary ammonium compounds of 1,1-dicyano-2-methoxy-2-oxothane-1-ide were synthesized within a single stage by stirring methanol solutions of tertiary amines with ethene-1,1,2,2-tetracarbonitrile (ETCN) at room temperature. In the reaction of ETCN with tertiary amines in methanol, processes occur that form the 1,1-dicyano-2-methoxy-2-oxoethane-1-ide fragment with simultaneous N-methylation. Crystal structures based on X-ray diffraction analysis of the obtained compounds were studied.

Base-catalyzed nucleophilic addition of carbon nucleophiles to the exocyclic double bond of 2-(5-aryl-4-methyl-2-oxo-1,2-dihydro-3H-pyrrol-3-ylidene)malononitriles afforded spiro-fused pyrrole derivatives, 7-amino-3-aryl-4-methyl-1-oxo-8-oxa-2-azaspiro[4.5]deca-3,6,9-triene-6-carbonitriles. The products can be regarded as rare structural analogs of biologically active spirans based on isatin.

A procedure has been developed for the synthesis of polyfunctional pyrano[3,4-c]pyrrole derivatives via intramolecular cyclization involving vicinal cyano and carboxamide groups on a pyran ring. 3-Amino-1-oxo-1,3a,4,7a-tetrahydropyrano[3,4-c]pyrrole-3a,7a-dicarbonitrile thus obtained react with organic amines to give stable ammonium salts and undergo hydrolysis to 1,3-dioxo-1,2,3,3a,4,7a-hexahydropyrano[3,4-c]pyrrole-3a,7a-dicarbonitriles in the presence of sulfuric acid.

The reaction of 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with gaseous hydrogen halides was used to obtain 2-amino-3-aroyl(acyl)-6-halopyridine-3,5-dicarbonitriles, which were subsequently converted to the respective 4-amino-1-aryl-6-halo-1-hydroxy-3-oxo-2,3-dihydro-1H-pyrrolo[3,4-c]pyridine-7-carbonitriles by treatment with concentrated sulfuric acid, followed by aqueous workup.

In reaction of tetracyanoethylene with ketones and HCl in 1,4-dioxane at 30–40°? 6-hydroxy-2-chloro-1,4,5,6-tetrahydropyridine-3,4,4-tricarbonitriles are formed.

1-[2-(1H-indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrole-2(5H)-ones were synthesized by the short heating of a mixture of tryptamine, aromatic aldehyde, and methyl acetylpyruvate followed by stirring at room temperature for one day.

The reaction of potassium 2-(2,2-dimethylpropanoyl)-1,1,3,3-tetracyanopropenide with an equimolar amount of 2-sulfanylethanol afforded 2-{5-amino-2-(tert-butyl)-4-cyano-2-[(2-hydroxyethyl)sulfanyl]- 2,3-dihydrofuran-3-ylidene}propanedinitrile, whereas 4-amino-1-(tert-butyl)-1,6-bis[(2-hydroxyethyl)- sulfanyl]-3-imino-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitrile was obtained in the reaction with excess 2-sulfanylethanol.

A novel fast, convenient and inexpensive synthesis of 1',3'-dioxo-1',3'-dihydrospiro[cyclopropane-1,2'-indene]-2,2,3,3-tetracarbonitrile and dimethyl 2,3-dicyano-1',3'-dioxo-1',3'-dihydrospiro[cyclopropane-1,2'-indene]-2,3-dicarboxylate is reported. These compounds undergo double carbanion cleavage under the action of alcohols resulting in the formation of stable salts, containing new allylic-type anions with potential application in organic electronics and as ionic liquid components.

A series of novel N,N-dialkyl-2-amino-3-cyanoisonicotinamides were synthesized in good to high yields (61–84%) via the reaction of 2-(5-aryl-2-oxo-1H-pyrrol-3(2H)-ylidene)malononitriles and amines according to the ANRORC process. The developed approach represents a novel method for the synthesis of functionalized nicotinonitriles.

A simple method for the synthesis of inaccessible gem-dinitro derivatives of pyridine is described. A wide range of 2-halogencycloalka[b]pyridine-3,4-dicarbonitriles are produced by the three-component reaction (ketone, TCNE, hydrohalic acid), side-chain nitration of latter with 60% nitric acid in a solvent-free conditions leads to the formation of gem-dinitro derivatives with high selectivity and without disturbing of other reaction centers.

2-Acyl-1,1,3,3-tetracyanopropenides undergo intermolecular reductive heterocyclization under the action of mercaptoethanol or sodium borohydride, resulting in the formation of 2-[5-amino-4-cyano-2-alkyl(aryl)furan-3(2 H ]-ylidene)malononitriles in high yields and excellent purities, These are of interest as potential precursors to organic nonlinear optical (NLO) materials and prospective antibiofilm antimicrobial agents.

Methyl aroylpyruvates reacted with 4-amino-N-carbamimidoylbenzene-1-sulfonamide in acetic acid–ethanol (1: 1) to give methyl 4-aryl-2-{[4-(carbamimidoylsulfamoyl)phenyl]amino}-4-oxobut-2-enoates which were found to exist in solution as mixtures of Z and E isomers.

The synthesis of 2-(dicyanomethylene)-1,2-dihydropyridine derivatives from the reactions of arylmethylidene derivatives of malononitrile dimers with 1,3-dicarbonyl compounds is described.

Reaction of arylmethylidene derivatives of malononitrile dimer with 1,3-cyclohexanediones in anhydrous methanol in the presence of sodium methylate as catalyst affords 4-amino-5-aryl-2-methoxy-6-oxo-5,6,7,8,9,10-hexahydrobenzo[b][1,8]naphthyridine-3-carbonitrile. In the presence of strong electron-donor substituents in the benzene ring the reaction takes another route resulting in 4-amino-2-aryl-6-methoxypyridine-3,5-dicarbonitriles.

Reactions of 3-amino-8-hydroxy-1,6-dioxo-2,7-diazaspiro[4.4]non-3-ene-4-carbonitriles with aqueous hydrohalic acid led to the formation of alkyl-substituted pyrrolo[3,4-c]-pyrrole-1,3,4,6-tetraones.

Reactions of 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with hydrazine hydrate followed by neutralization led to the formation of 2-amino-4-[hydrazono(aryl)methyl]-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles.

lMethyl 6-Amino-3-acyl-4-aryl-5-cyano-4H-pyran-2-carboxylates, 9-aryl-12-imino-10,11 dioxatricyclo-[5.3.2.01,6]-dodecan-7,8,8- tricarbonitriles, 2-R-1,2,5,6,7,8-hexahydroquinoline-3,3,4,4- tetraсarbonitriles were synthesized. The antiproliferative activity of obtained compounds was investigated. At a concentration of 10 μM test substances activity higher than that of the drug busulfan and cisplatin showed a compounds containing in its composition fragment of ethyl 1,1,2,2-tetracarbonitrile - 2-R-1,2,5,6,7,8- hexahydroquinoline-3,3,4,4-tetraсarbonitriles.

The reaction of sodium 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with hydroiodic acid at heating led to the formation of 1-alkyl(aryl)-4-amino-6-iodo-3-oxo-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitriles.

3-Benzoylcyclopropane-1,1,2,2-tetracarbonitrile reacted with water to give 2-benzoyl-1,3-dicyanocyclopropane-1-carboxamide as a result of hydrolysis of the cyano group in the trans position with respect to the carbonyl group and subsequent decarboxylation. The reaction of 3-benzoyl-3-methylcyclopropane-1,1,2,2-tetracarbonitrile with water involved heterocyclization with participation of the carbonyl group and cis-cyano groups, leading to 8-methyl-3,6-dioxo-1-phenyl-2,7-diazatricyclo[3.2.1.04,8]octane-4,5-dicarbonitrile. Hydrolysis of 3-alkylcyclopropane-1,1,2,2-tetracarbonitrile followed both reaction paths to produce mixtures of products, including 7-alkyl-4-amino-7-hydroxy-1,9-dioxo-3,8-diazatricyclo[4.3.0.01,5]non-3-ene-5-carbonitriles. In all cases, the three-membered ring was retained.

The reaction of 5,6-dialkyl-2-halopyridine-3,4-dicarbonitriles with alcoholic ammonia under elevated pressure gave 5,6-dialkyl-2-aminopyridine-3,4-dicarbonitriles as a result of nucleophilic replacement of the halogen atom by amino group. 6,7-Dialkyl-4-halo-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diimines were formed in analogous reaction at room temperature in the presence of potassium carbonate.

A new approach to the regioselective synthesis of polyfunctional 3H-pyrroles from 4-oxoalkane-1,1,2,2-tetracarbonitriles is described. 5-Amino-3-(2-aryl-2-oxoethyl)-3H-pyrrol-3,4-dicarbonitriles are prepared from 4-aryl-4-oxobutane-1,1,2,2-tetracarbonitriles. Diastereomeric 5-amino-2-morpholin-4-yl-3-(2-oxocyclohexyl)-3H-pyrrole-3,4-dicarbonitriles were obtained from 1-(2-oxocyclohexyl)ethane-1,1,2,2-tetracarbonitriles.

2-Acyl(aroyl)-1,1,3,3-tetracyanopropenides reacted with hydrogen halides along two concurrent pathways with formation of furan or pyridine derivatives. The reaction in butan-2-ol afforded 2-amino-4-acyl-(aroyl)-6-halopyridine-3,5-dicarbonitriles, whereas the major products in the reactions with HCl and HBr in aqueous solution were the corresponding 2-(5-amino-2-aryl-2-chloro(bromo)-4-cyano-2,3-dihydrofuran-3-ylidene)malononitriles. The reaction with aqueous hydrogen iodide was accompanied by reductive deiodination and produced 2-(5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidene)malononitriles.

Reactions of 2-aroyl-1,1,3,3-tetracyanopropenides with thiols in acid medium led to the formation of the corresponding 2-alkylsulfanyl-substituted 2-(5-amino-2-aryl-4-cyano-2,3-dihydrofuran-3-ylidene)propanedinitriles.

The reaction of 2,2,3,3-tetracyanocyclopropyl ketones with hydrazine involved the addition at the carbonyl and cyano groups and resulted in the formation of previously unknown polycyclic systems whose common feature was the presence in the structure of a pyridazine ring. In the general case 3-substituted 6-amino-8-oxo-4,5,7-tptriazatricyclo[4.3.0.02.9]-non-3-ene-1,9-dicarbonitriles were obtained. The reaction with 3-pivaloylcyclopropane-1,1,2,2-tetracarbonitrile took another route with the opening of the three-membered ring and the formation of 3-amino-7a-tert-butyl-6-oxo-5,6,7,7a-tetrahydro-4aH-pyrrolo[2,3-c]pyridazine-4,5-dicarbonitrile.

2′-Oxo-1′,2′-dihydrospiro[cyclopropane-1,3′-indole]-2,2,3,3-tetracarbonitriles reacted with oxygencentered nucleophiles to form addition products at the cyano groups with conservation of the three-membered ring. Reactions of the title compounds with alcohols required the presence of base catalyst, and the products, 2-amino-4,4-dialkoxy-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles, were converted into the corresponding 2-imino-2′,4-dioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles and 2,2′,4-trioxospiro[3-azabicyclo[3.1.0]hexane-6,3′-indole]-1,5-dicarbonitriles by the action of acetic and sulfuric acids, respectively. The reactions with ketone oximes occurred in the absence of a catalyst, yielding 2-amino-4,4-bis(alkylideneaminooxy)-2′-oxo-1′,2′-dihydrospiro[3-azabicyclo[3.1.0]hex-2-ene-6,3′-indole]-1,5-dicarbonitriles. The reactions with thiols, aliphatic amines, and anilines were accompanied by opening of the three-membered ring. In the reactions with triphenylphosphine and thiols 2-(2-oxo-2,3-dihydro-1H-indol-3-ylidene)malononitrile was obtained, while morpholine and N,N-dimethylaniline gave rise, respectively, to 3,3-diaryl-and 3,3-dimorpholino-1H-indol-2(3H)-ones and tri- and dicyanoethylene derivatives.

Dihydropyridines are an important group of heterocyclic compounds and they can show different forms of biological activity [1], e.g., antihypertensive [2], antiarrhythmic [3], bioprotective [4], and hepatoprotective [5]. Amongst this group, 1,2(1,6)-dihydropyridines are very poorly represented, that is linked to the small number of methods for preparing them. With the aim of developing novel methods for the synthesis of 1,2(1,6)-dihydropyridines we have studied the reduction process of polyfunctional 5,6-dialkyl-2-chloropyridine-3,4-dicarbonitriles 1. These compounds were prepared according to a three-component method developed by us from tetracyanoethylene, ketones, and concentrated hydrochloric acid [6]. A special feature of the pyridines 1 is the presence of several reactive centers which can undergo a reduction, viz. two cyano groups, the C–Cl bond, and the pyridine ring. This fact complicates the problem of a targeted reduction of the C=N bond in the pyridine ring. It should be noted that, up to the time of our study, the literature has reported reduction processes of structural analogs of pyridines 1, viz compounds containing a 2-halopyridine-3-carbonitrile fragment including other heterocycles in composition. Hence there has been reported a selective reduction of a C–Cl bond by hydrogenolysis in the presence of Pd/C [7], by the action of zinc dust in acidic medium [8], and by the action of a solution of hydriodic acid, iodine, and red phosphorus [9]. In the hydrogenolysis of 2,6-dibromopyridine3,5-dicarbonitrile in the presence of Pd/CaCO3 a simultaneous reduction of the C–Br and C=N bonds of the pyridine ring occurs [10]. The process of reduction of pyrido[2,3-d]pyrimidines has also been reported using NaBH4 in which the pyridine ring was reduced with retention of the halogen to yield 1,4-dihydropyridine derivatives [11]. A selective reduction of the cyano group to an aminomethyl has been reported for 2-chloropyridine-3-carbo-nitrile reaction with NaBH4 in the presence of CoCl2 or with hydrogen using Raney nickel [12]. We have developed a method for the selective reduction of the C(6)=N bond in the pyridines 1a-d which is achieved via their reaction with sodium borohydride in methanol at 20oC for 30 min. The result of this reaction is the formation of the 5,6-dialkyl-2-chloro-1,6-dihydropyridine-3,4-dicarbonitriles 2a-d in 74-91% yields. _______ *To whom correspondence should be addressed, e-mail: oleg.ershov@mail.ru.

We now propose a new synthetic approach to photochromic diarylethenes, which is based on the reaction of tetracyanoethylene with ketones as key intermediate step. Tetracyanoethylation of ketones has been well documented; however, there are almost no published data on reactions of aryl arylmethyl ketones with tetracyanoethylene. Adducts of tetracyanoethylene with ketones of the general formula R(CO)CH2R′ were used as starting compounds to obtain heterocycles containing an RC=CR′ fragment [4–10]. Analogous reactions with aryl arylmethyl ketones Ar(CO)CH2Ar could give rise to various 1,2-diarylethenes as new potential photochromes. We were the first to react tetracyanoethylene with 1,2-diarylethanones Ia and Ib in the presence of a catalytic amount of hydrochloric acid. As a result, we isolated 3,4-diaryl-4-oxobutane-1,1,2,2-tetracarbonitriles IIa and IIb. The substrates were deoxybenzoin (Ia), the parent compound of the 1,2-diarylethanone series, and 1,2-bis(2,5-dimethylthiophen-3-yl)ethanone (Ib). The latter was selected taking into account that diarylethenes containing thienyl substituents are most promising from the viewpoint of the design of practically useful photochromic devices [1]. Ketone Ib was synthesized in a number of steps starting from hexane2,5-dione [11].

A procedure for the synthesis of 2,2,3,3-tetracyanocyclopropyl ketones has been developed on the basis of three-component Wideqvist reaction of dihydroxymethyl ketones, 2-bromomalononitrile, and malononitrile. The presence of five electron-withdrawing groups in the resulting cyclopropyl ketones determines high acidity of proton in the cyclopropane ring. Facile deprotonation by the action of bases promotes opening of the three-membered ring with formation of either 1,1,3,3-tetracyanopropenides or (in the presence of alcohols or oximes), [2-alkoxy(aminooxy)-5-amino-4-cyanofuran-3(2H)-ylidene]malononitriles. The reaction with acetone oxime was not accompanied by cleavage of the three-membered ring, and nucleophilic attack was directed at the cyano groups in the trans position with respect to the carbonyl group to give the corresponding (1R*,5S*,6R*)-4-amino-2,2-bis(prop-2-ylideneaminooxy)-3-azabicyclo[3.1.0]hex-3-ene-1,5-dicarbonitriles.

In reaction of alkyl 2-amino-5,6-dialkyl-3-cyanopyridine-4-carboxylates with isocyanates formed unstable ureas, and with nitrous acid at 60–70°C alkyl 5,6-dialkyl-2-oxo-1,2-dihydro-4-pyidinecarboxylates were obtained. It was shown for the latter that their reactions with organic acids and amides occurred at the cyano group, and the alkaline hydrolysis involved the ester group.

A simple method for the synthesis of inaccessible gem-dinitro derivatives of pyridine is described. A wide range of 2-halogencycloalka[b]pyridine-3,4-dicarbonitriles are produced by the three-component reaction (ketone, TCNE, hydrohalic acid), side-chain nitration of latter with 60% nitric acid in a solvent-free conditions leads to the formation of gem-dinitro derivatives with high selectivity and without disturbing of other reaction centers.

Dihydropyridines are an important group of heterocyclic compounds and they can show different forms of biological activity [1], e.g., antihypertensive [2], antiarrhythmic [3], bioprotective [4], and hepatoprotective [5]. Amongst this group, 1,2(1,6)-dihydropyridines are very poorly represented, that is linked to the small number of methods for preparing them. With the aim of developing novel methods for the synthesis of 1,2(1,6)-dihydropyridines we have studied the reduction process of polyfunctional 5,6-dialkyl-2-chloropyridine-3,4-dicarbonitriles 1. These compounds were prepared according to a three-component method developed by us from tetracyanoethylene, ketones, and concentrated hydrochloric acid [6]. A special feature of the pyridines 1 is the presence of several reactive centers which can undergo a reduction, viz. two cyano groups, the C–Cl bond, and the pyridine ring. This fact complicates the problem of a targeted reduction of the C=N bond in the pyridine ring. It should be noted that, up to the time of our study, the literature has reported reduction processes of structural analogs of pyridines 1, viz compounds containing a 2-halopyridine-3-carbonitrile fragment including other heterocycles in composition. Hence there has been reported a selective reduction of a C–Cl bond by hydrogenolysis in the presence of Pd/C [7], by the action of zinc dust in acidic medium [8], and by the action of a solution of hydriodic acid, iodine, and red phosphorus [9]. In the hydrogenolysis of 2,6-dibromopyridine3,5-dicarbonitrile in the presence of Pd/CaCO3 a simultaneous reduction of the C–Br and C=N bonds of the pyridine ring occurs [10]. The process of reduction of pyrido[2,3-d]pyrimidines has also been reported using NaBH4 in which the pyridine ring was reduced with retention of the halogen to yield 1,4-dihydropyridine derivatives [11]. A selective reduction of the cyano group to an aminomethyl has been reported for 2-chloropyridine-3-carbo-nitrile reaction with NaBH4 in the presence of CoCl2 or with hydrogen using Raney nickel [12]. We have developed a method for the selective reduction of the C(6)=N bond in the pyridines 1a-d which is achieved via their reaction with sodium borohydride in methanol at 20oC for 30 min. The result of this reaction is the formation of the 5,6-dialkyl-2-chloro-1,6-dihydropyridine-3,4-dicarbonitriles 2a-d in 74-91% yields. _______ *To whom correspondence should be addressed, e-mail: oleg.ershov@mail.ru.

It was discovered by means of dynamic NMR that the 1-(cis-1-methylprop-1-en-1-yl)-1,2-dimethyl-acenaphthylenonium ion generated under conditions of “long life” for carbocations underwent fast (ΔG#35.8 kJ mol−1 at −103°C) degenerate 1,2-shift of the cis-dimethylvinyl group. Quantum-chemical calculations by DFT method predict lower rate of 1,2-shift for the trans-dimethylvinyl group compared to cis-dimethylvinyl group and dependence on the cations conformation of the rates of these processes and of the rearrangement mechanism into the ions of phenalenyl type.

Reactions of 2,2,3,3-tetracyanocyclopropanecarboxylic acid with potassium, sodium, calcium, strontium, barium, ammonium, N-methylpyridinium, N-methylquinolinium, N,N-dimethyl-1,4-diazabicyclo-[2.2.2]octane-1,4-diium, and N,N-dimethylanilinium iodides afforded the corresponding 3-cyano-4-dicyanomethylidene-5-oxo-4,5-dihydro-1H-pyrrol-2-olates.

4-Aryl-3-methyl-4-oxobutane-1,1,2,2-tetracarbonitriles reacted with morpholine to give 8-amino-3aryl-1-imino-4-methyl-6-(morpholin-4-yl)-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles. Ar = Ph (a), 4-ClC6H4 (b), 4-MeC6H4 (c). 4-Oxoalkane-1,1,2,2-tetracarbonitriles are extensively studied representatives of the series of polynitrile compounds. Derivatives of 4-oxoalkane-1,1,2,2tetracarbonitriles are known as potential antitumor agents [1] and coordination polymers with interesting topology [2]. We now perform extensive studies on the transformations of 4-oxoalkane-1,1,2,2-tetracarbonitriles by the action of nitrogen-centered nucleophiles [3]. 4-Oxoalkane-1,1,2,2-tetracarbonitriles were reported to react with ammonia and amines to form 3-amino-7oxo-4,6-diazabicyclo[3.2.1]oct-2-ene-1,2-dicarbonitriles [4], 3-amidinio-2-aminopyridine-4-carboxylates [5], diethylammonium 3,4-dicyano-5,6,7,8-tetrahydroquinolin-2-olates [6], and ammonium 4-aryl-4oxo-1,1,2-tricyanobut-2-en-1-ides [7]. We recently showed that the reaction of 4-oxoalkane-1,1,2,2-tetracarbonitriles with morpholine leads to 5-amino-2(morpholin-4-yl)-3H-pyrrole-3,4-dicarbonitriles [8, 9] and found that nitrogen-centered nucleophiles preferably add to the β-cyano groups of polyelectrophilic tetranitriles. The resulting compounds are representatives of a poorly explored class of aza heterocycles, 3H-pyrroles, which may be regarded as nitrogen-containing cyclopentadiene analogs. Despite limited published data, some 3H-pyrroles were found to exhibit antimicrobial and antitumor activity [10–12]. With a view to synthesize new functionally substituted 3H-pyrrole derivatives, we extended the series of 4-oxoalkane-1,1,2,2-tetracarbonitrile substrates and examined their reaction with morpholine in more detail. The reactions of 4-aryl-3-methyl-4-oxobutane-1,1,2,2DOI: 10.1134/S1070428013060110

An unusual direction has been found for the interaction of alkyl 5,6-dialkyl-2-amino-3-cyanopyridine-4-carboxylates with primary amines leading to the formation of 2,6,7-trialkyl-4-amino-2,3-dihydro-1H-pyrrolo[3,4-c]pyridine-1,3-diones.

Reactions of 2-methylcyclohexanone and menthone with tetracyanoethylene gave 2-(1,1,2,2-tetracyanoethyl)cyclohexanones which underwent quantitative transformation in the solid phase into 3,4-cyanosubstituted 2-aminopyrans in 2-3 days at room temperature. 2-Methyl-2-(1,1,2,2-tetracyanoethyl)cyclohexanone reacted with hydroiodic acid to afford 8a-hydroxy-2-iodo-4a-methyl-1,4,4a,5,6,7,8,8a-octahydroquinoline-3,4,4-tricarbonitrile. The reaction of 2,2'-methylenedi(cyclohexanone) with tetracyanoethylene resulted in formation of 7-imino-4,5-tetramethylene-2'-oxo-6-oxabicyclo[3.2.1]octane-2-spiro-1'-cyclohexane-1,8,8-tricarbonitrile.

3-Amino-4-aryl-1-dicyanomethylidene-1,3a,4,4a-tetrahydrocyclopropa[c]pyrrole-3a,4a-dicarbonitriles were synthesized by reaction of 2-amino-4-arylbuta-1,3-diene-1,1,3-tricarbonitriles (arylmethylidene derivatives of malononitrile dimer) with bromomalononitrile.

Reaction of tetracyanoethylene with α,β-unsaturated ketones was investigated. 3-R1-4-R2-6-R3-5-oxo-1,1,2,2-cyclohexanetetracarbonitriles, unsaturated tetracyanoalkanones, 3-R-5,5-dihydroxy-1,1,2,2-cyclohexanetetracarbonitriles, 1,2,2-tricyano-3-R-5-oxo-1-cyclohexanecarboxamides, 3-R1-4-R2-8-R3-5-hydroxy-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles were synthesized.

2-Aminoindoles are subject to attack by tetracyanoethylene at position 3 with, when possible, subsequent ring closure.

The scission of the urea group in 5-alkyl-2-amino-3,4-dicyano-N-ureidopyrroles on boiling in KOH solution in DMSO was observed to give 5-alkyl-1,2-diamino-3,4-dicyanopyrroles which were used for the synthesis of pyrrolo[1,2-b][1,2,4]triazepines by reaction with acetylacetone.

2,12-Diaryl-4-(arylmethyleneamino)-8-methyl-5,6,10,11,11-pentacyano-1,3,8-triazatricyclo[7,3,0,03,7]dodeca-4,6,9-trienes (VIIa-c) are synthesized on methylation of 2,5-diaryl-3,3,4,4-tetracyanopyrrolidines with diazomethane in dioxan. Their structure was confirmed by an x-ray structural investigation of a single crystal of compound (VIIa).

Using the system of tetracyanoethylene, ammonium acetate and a carbonyl compound, the preparation of 2-[5-amino-2,3-dihydro-4H-imidazol-4-ylidene]malononitriles was carried out. The structures of these new dihydroimidazoles were determined by NMR experiments and by X-ray crystallography.

The reaction of tetracyanoethylene and isobutyraldehyde or 2-ethylbutanal in an excess of a hydrohalogen acid yields 2-halo-6-hydroxy-5,5-dimethyl(ethyl)-5,6-dihydro-3,4,4(1H)-pyridinetricarbonitriles, the crystal and molecular structures of which were characterised by IR, NMR, MS and X-ray analysis.