Five-membered-ring-substituted 1-methyl-1H-indeno[1,2-b]pyridines

1-Methyl-1H-indeno[1,2-b]pyridine and 1-methyl-1H-5-(, -dicarbomethoxyvinyl)-(formyl, acetyl)indeno[3,2-b]pyridines were obtained by treatment of N-methyl-4-azafluorenium iodide, as well as mixtures of it with acetylenedicarboxylic ester, dimethylformamide (DMF), and phosphorus oxychloride or acetic anhydride, with bases. 4-Azafluoronenone was used to synthesize 9-(p-methoxyphenyl)-4-azafluoren-9-ol, which was reduced to 9-(p-methoxyphenyl)-4-azafluorene, and 1-methyl-1H-5-(p-methoxyphenyl)indeno[3,2-b]pyridine was obtained from the methiodide of the latter.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1382–1386, October, 1981.     

Cyanoethylation of azafluorenes and syntheses of alcohols containing an azafluorene fragment

Isomeric (with respect to the position of the nitrogen atom) azafluorenes were cyanoethylated. The resulting 9,9-bis(-cyanoethyl) derivatives were converted to the corresponding dibasic acids and their diesters. The latter were subjected to the Dieckmann reaction to obtain spiro compounds with azafluorene and cyclohexene fragments. The analogous spirans with 1,3-dioxalane and 1,3-dioxane rings were obtained from 3-methyl-2-azafluorenone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1668–1672, December, 1982.     

Conversions of 9-chloro-4-azafluorene to azalenes

The iodomethylate of 9-chloro-4-azafluorene is converted to 1H-1-methyl-indeno[1,2-b]pyridine when treated with base. We discuss the structure of compounds containing azalene fragments, which are formed upon heating 9-chloro-4-azafluorene. We discuss some considerations concerning the nomenclature of azulenes with the azafluorene skeleton.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 915–920, July 1992.     

1-(Fluoren-2-yl)-2-(2-azafluoren-3-yl)ethene and 1-(fluoren-2-yl)-2-(2H,2-methylindeno[2,3-c]pyridine)ethene

Condensation of 3-methyl-2-azafluorene with 2-formylfluorene results in the formation of a compound containing a polyconjugated system and two acidic CH centers, namely, 1-(fluoren-2-yl)-2-(2-azafluoren-3-yl)ethene. The conversions of this compound upon treatment with alkali have been studied by electronic absorption spectroscopy. The methyl iodide derivative of this base was used as an intermediate in the preparation of a pseudo-azulene, 1-(fluoren-2-yl)-2-(2H, 2-methylindeno[2,3-c]pyridine)ethene.Translated from Khimiya Geterotsiklicheskikh Soedinenii No. 5, pp. 657–659, May, 1987.     

Synthesis of 9-diazo-4-azafluorenes

Stable diazo compounds of the azafluorene series, viz., 9-diazo-4-azafluorenone and 1,3-diphenyl-4-azafluorene, were obtained from 4-azafluorenone and 1,3-diphenyl-4-azafluorene tosylhydrazones. 1,2-Dicarbomethoxyspiro(4-azafluorene-9,3-cyclopropane) was obtained from 4-azafluorenone tosylhydrazone, and 4,5-dicarbomethoxyspiro(4-azafluorene-9,3-pyrazolenine) was obtained from 9-diazo-4-azafluorene. It is assumed that the product in the latter case is obtained as a result of reaction of a carbene, viz., 4-azafluorenylidene carbene, which is formed from 9-diazo-4-fluorene, with dimethyl acetylenedicarboxylate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 951–953, July, 1979.     

Condensation of N-(piperidylidene-4)arylamines with acetylenedicarboxylic esters

The substituted piperidines, N-(piperidin-3-en-4-yl)-N-(1,2-dimethoxycarbonyl-etheno)arylamine and 1-aryl-3,4,5,6-tetramethoxycarbonyl-1,2-dihydrospiro[cyclo-[pyridine-2,4-piperidine], were synthesized by the condensation of acetylenedicarboxylic ester with an azomethine, obtained from a -piperidone. It was found that the amounts of 11 and 12 addition compounds obtained depends on the ratio of starting reagents. Compounds isomeric at the vinyl group were examined in the case of one of the 11 addition compounds. N-(1,2,5-trimethylpiperidin-4-yl)-N-(1,2-dimethoxycarbonyletheno)aniline was prepared by two methods.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 943–946, July, 1986.     

Characterization of oligomerization of a peptide from the ebola virus glycoprotein by small-angle neutron scattering

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) studies showed that model peptides QNALVCGLRQ (G33) and QNALVCGLRG (G31) corresponding to region 551–560 of the GP protein of the Sudan Ebola virus are prone to oligomerization in solution. Both peptides can form amyloid-like fibrills. The G33 peptide forms fibrils within one day of incubation, whereas the fibrillogenesis of the G31 peptide is observed only after incubation for several months. The possible role of the observed processes in the pathogenesis and the possibility of applying a combination of the TEM and SANS techniques to search for new compounds that are able to influence the protein oligomerization are discussed.     

Arylidenehydrazono-2(4)-azafluorenes

Previously unknown unsymmetrical azines with arylidene and azafluorenylidene fragments were obtained. Some of the geometric isomers of 3-methyl-9-benzyl-idene(4-methoxybenzylidene)hydrazono-2-azafluorenes were isolated. The longwave absorption bands in the electronic spectra of these compounds were interpreted on the basis of the experimental and calculated data (the PPP method).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 248–253, February, 1986.     

Benzylation of γ-N- (arylamino) piperidines via the wallach reaction

N-Aryl(aralkyl)-N-(4-piperidinyl)benzylamines have been prepared from -N-(arylamino) piperidines using the Wallach reaction. Carbonyl-containing compounds have been detected as impurities in these products using mass spectrometry. A possible mechanism is discussed for the Wallach reaction, based on the structures of the secondary amine starting materials used in this study.Translated from Khimiya Geterotsiklicheskikh Soednenii, No. 8, pp. 1078–1083, August, 1988.     

Coordination ability of N,N’-disubstituted 9,10-phenanthrenediimines

The ability of N,N’-disubstituted 9,10-phenanthrenediimines in neutral, monoand direduced states to act as bidentate ligands in main-group-metal and transition-metal complexes has been demonstrated for the first time. The formation of metal complexes with the radical anion form of phenanthrenediimines stabilized through the formation of contact pairs (for Li) or chelate complexes (for Rh) has been detected.