Macrocycles,derivatives of nitrogen-containing heterocycles 3. Synthesis of di(imidazo[1,5-a]quinoxalina)-2(1,3)-benzadithiacycloalkaphanes

A three-step method for the construction of di(imidazo[1,5-a]quinoxalina)-2(1,3)-benza-dithiacycloalkaphanes has been developed, which includes introduction of a haloalkyl group of various length and nature into 1,3-bis(4(5H)-oxo-3-phenylimidazo[1,5-a]quinoxalin-1-yl)-benzene at the carbamoyl fragment, transformation of the bishalo-substituted compound thus obtained to bisthiol, and coupling of the latter to a disulfide.     

Synthesis of nitrogen-containing heterocycles. 4. A facile route to new 1, 2, 4-triazole derivatives

The reaction of amino-N(4),N(4)-dimethylaminornethylenehydrazones 1 of some aliphatic carbonyl compounds with ethyl ethoxymethylenecyanoacetate 2 gave directly symmetrical gem-bis(3-dimethylamino-1, 2, 4-triazol-1-yl)alkanes 4 and (3-dimethylamino-1, 2, 4-triazol-1-yl)alkenes 5 at room temperature, with the former being major product. On the other hand, the reaction of amino- N (4)-methylaminomethylenehydrazone homologue 1 of aliphatic ketone with 2 gave ethyl 2-alkyl-5-methylamino[1, 2, 4]triazolo[1, 5-c]pyrimidine-8-carboxylate 7 as the only product with elimination of alkane.     

Saturated nitrogen-containing heterocycles. VIII. Synthesis and properties of some substituted pyrrolidylalkanols

Phenyl-substituted pyrrolidylalkanols were synthesized by hydrogenation of the corresponding furan amines in acidic aqueous solution in the presence of nickel on diatomaceous earth. Terephthalates, carbamates, and other pyrrolidylalkanol derivatives were obtained. The ability of (2-pyrrolidyl)-3-alkanols to form an intramolecular hydrogen bond was studied by IR spectroscopy.See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 186–190, February, 1976.     

Saturated nitrogen-containing heterocycles VI. Alkyl-2-thiopyrrolidones and their acetyl derivatives

A number of 5-alkyl-2-thiopyrrolidones and 1-methyl-5-alkyl-2-thiopyrrolidones were synthesized by the reaction of the corresponding pyrrolidones with phosphorus pentasulfide. The 5-alkyl-2-thiopyrrolidones were acylated.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 333–335, March, 1972.     

Synthesis of nitrogen-containing heterocycles. 3. Formation and structure of new 1,2,4-triazole derivatives

Treatment of N(3)-[(2-cyano-2-ethoxycarbonyl)vinyl]amino-N(4),N(4)-dimethylaminomethylenehydrazones of aromatic carbonyl compounds with hot acetic acid resulted in the formation of symmetrical gem-bis-(3-dimethylamino-1,2,4-triazol-1-yl)methanes, (3-dimethylamino-1,2,4-triazol-1-yl)arylmethyl acetates, and (3-dimethylamino-1,2,4-triazol-1-yl)alkenes of a gem-diaryl type depending upon whether the carbonyl compound was aldehyde or ketone.     

Saturated nitrogen-containing heterocycles. 13. Perhydroacridines. Synthesis and stereochemistry

The configurations of the perhydroacridines formed in the catalytic hydroamination of threo-methylenedicyclohexanone and the product of its cyclization — 2-hydroxy-2,3-tetramethylenebicyclo[3.3.1]nonan-9-one — were established by means of the ¹³C NMR spectra and alternative synthesis. It is shown that isomers with cis-anti-cis and cis-syn-cis configurations are formed as a result of the reactions. The results of x-ray diffraction analysis are presented for cis-syn-cis-N-(2-hydroxyethy1)perhydroacridine.See [1] for Communication 12.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1650, December, 1987.     

Synthesis of a number of derivatives of alkaloids and of nitrogen-containing heterocycles and their anticholinesterase activities

N-Methyl- and N-phenylcarbamates based on a number of alkaloids and nitrogen-containing heterocycles have been synthesized, and they have proved to be weak irreversible inhibitors of acetylcholinesterase and butyrylcholinesterase. It has been shown that the choline fragments of the above-mentioned carbamates and their β-methylcholine analogs are reversible inhibitors of both cholinesterases and make a substantial contribution to the anticholinesterase activity. Selective inhibitors of ACE and BuCE have been found among the compounds synthesized.     

Saturated heterocycles. 136 . Synthesis of 2-substituted 2-azapyracridone derivatives

By means of Substitution, addition and condensation on the secondary nitrogen of 9-methyl-1,2,3,4-tetrahydro-2-azapyracridone (6) , twenty new azapyracridones were prepared.     

Synthesis of a number of derivatives of alkaloids and of nitrogen-containing heterocycles and their anticholinesterase activities

N-Methyl- and N-phenylcarbamates based on a number of alkaloids and nitrogen-containing heterocycles have been synthesized, and they have proved to be weak irreversible inhibitors of acetylcholinesterase and butyrylcholinesterase. It has been shown that the choline fragments of the above-mentioned carbamates and their -methylcholine analogs are reversible inhibitors of both cholinesterases and make a substantial contribution to the anticholinesterase activity. Selective inhibitors of ACE and BuCE have been found among the compounds synthesized.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 825–831, November–December, 1988.     

Diazocarbonyl derivatives of heterocycles. 7. Synthesis,properties, and structure of 2,4-diazido-6-diazoacetylpyrimidine

The reaction of 2,4-dichloro-6-diazoacetylpyrimidine with sodium azide to give 2,4-diazido-6-diazoacetylpyrimidine has been examined, and the crystal structure of the latter, and its 1,3-dipolar cycloadditions at the carbonyl group, studied.For Communication 6, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 515–519, April, 1990.     

Synthesis of fused polycyclic nitrogen-containing heterocycles via cascade cyclization

A novel strategy for the synthesis of fused polycyclic-nitrogen containing heterocycles via cascade cyclization is described. The methodology involves condensation of 1-(2-aminophenyl)-9H-β-carboline-3-carboxylic acid amide with isothiocyanates followed by in situ treatment of the resulting thioureas with HgCl₂ for 1 h at rt. The one-pot cascade cyclization leads to interesting changes in molecular structure and an increase in molecular complexity. A mechanistic rationale for the cascade cyclization is discussed.     

Stereochemistry of nitrogen-containing heterocycles

The reduction of the - and -isomers of 2-methyl-4-oxooctahydro-1-pyrindine in the presence of Raney nickel and sodium in ethanol has been studied, and four isomers of 2-methyloctahydro-1-pyrindin-4-ol have been obtained. On the basis of an analysis of IR spectra, basicity constants, and the conditions for the reduction of the ketones, the most probable spatial structures have been assigned to all four piperidols.For part XIV, see [1].     

Acid-base properties of five-membered nitrogen-containing heterocycles (review)

The acid-base properties of five-membered nitrogen-containing heterocycles with one, two, three, and four nitrogen atoms in the ring are discussed. The factors that determine the properties of these compounds as acids and bases are analyzed. The problems that arise in comparing the basicities of heterocycles, the protonation of which is described by different acidity scales are stressed. A significant amount of space is allotted to an examination of the acid-base properties of nitrogen-containing heterocycles in the gas phase and to the use of quantum-chemical methods in the study of the protolytic equilibria of these compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 579–592, May, 1988.     

Saturated nitrogen-containing heterocycles V. Synthesis of 5-alkyl-n-(β-hydroxyethyl)-2-pyrrolidones

A number of 5-alkyl-N-(-hydroxyethyl)-2-pyrrolidones were synthesized by the reductive ethanolamination of ethyl esters of -keto carboxylic acids in the presence of Raney nickel.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 331–332, March, 1972.     

N-2-亚甲基-呋喃-二茂铁芳胺衍生物的合成与晶体结构及电化学性质

以邻、间、对-二茂铁苯胺为原料,合成了新的含呋喃二茂铁苯基席夫碱衍生物,还原得到N-2-亚甲基-呋喃-二茂铁芳胺衍生物,通过元素分析,IR,1H NMR和X-射线单晶衍射等分析手段,确证了标题化合物的组成和结构,化合物2 c单晶结构解析表明,2 c属于单斜晶系,P2/n空间群;其HOMO轨道主要由Fe原子及茂环上C的原子轨道组成,LUMO主要由O、N和苯环上C原子构成;电化学实验证明:邻、间、对化合物的电化学性质相似,苯环上取代基位置的不同,对化合物在电极表面的扩散系数影响不大,但对反应速率常数有较大的影响.     

Synthesis of nitrogen-containing heterocycles. 7 Reaction of aliphatic diaminomethylenehydrazones with hindered ethoxymethylenecyanoacetate

Aliphatic diaminomethylenehydrazones 1 were reacted with ethyl 2-cyano-3-ethoxy-2-pentenoate 2 to give a number of heterocycles in low to moderate yields, according to the substitution pattern and the size of substituent. When 1 carried a single methyl group on the terminal nitrogen, it gave preferentially 6-oxo-1,6-dihydropyrimidines 4 incorporating N(4) into the ring. In contrast, the reaction between 1c or 1d and 2 led to 6-imino- and 6-oxo-1, 6-dihydropyrimidines 7 and 8 along with 3 . When the alkylidene moiety was bulky, 1e and 1f , the similar reaction gave 3 in high yields without any cyclized product. Upon exposure to acid, compound 3 yielded 6-oxo-1,6-dihydropyrimidines 6 , [1,2,4]triazolo[1,5-c]pyrimidine-8-carboxylate 5 and N-alkenyl-1,2,4-triazoles 9 in addition to 7 and 8 in proportions dictated by the nature of the substituents of 1 . The structural assignment and reaction mechanism are discussed.     

Saturated nitrogen-containing heterocycles. 14. Synthesis and three-dimensional structures of n-r-dicyclopenta[b,e]piperidines

The catalytic hydroamination of threo-methylenedicyclopentanone using ammonia, methylamine, and monoethanolamine as the aminating agents proceeds stereospecifically with the formation of N-R-cis-syn-cis-dicyclopenta[b,e]piperidines (R=H, CH₃, CH₂CH₂OH). The structures of the latter were proved by ¹³C NMR spectroscopy. The molecular structure of N-(-hydroxyethyl)cis-syn-cis-dicyclopenta[b,e]piperidinium acid tartrate was investigated by x-ray diffraction analysis, and the absolute configuration of its chiral centers was determined.See [1] for Communication 13.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1094–1099, August, 1988.     

Synthesis,structure and electrochemical properties of two new unsymmetrical tetrathiafulvalene derivatives

Two new unsymmetrical tetrathiafulvalene (TTF) derivatives, 2,3‐bis(cyanoethylthio)‐6,7‐(methyl‐ethylenedithio)tetrathiafulvalene ( 6a ) and 2,3‐bis(cyanoethylthio)‐6,7‐(cyclopentodithio)tetrathiafulvalene ( 6b ), have been prepared and characterized by NMR, MS, IR and Elemental analyses. The molecular structures have been determined by X‐ray crystallography. Their redox properties have been investigated by cyclic voltammetry in dichloromethane solution and each compound shows two reversible single‐electron redox couples.