Cyclic dithio-carbenium ion salts and their conversion to ketene dithioacetals

1,2-Ethanedithiol and 1,3-propanedithiol were treated with perchloric acid in acetic anhydride to give 2-methyl-1,3-dithiolan-2-yl and 2-methyl-1,3-dithian-2-yl perchlorates, respectively, which were converted to ketene dithioacetals by deprotonation with tertiary amines.     

Reduction of 9-aminoarylacridines and their salts

9-Formamidoarylacridans are obtained in the reduction of 9-aminoarylacridines with a free amino group by means of formic acid in the presence of triethylamine. Under these conditions N,N-dialkyl derivatives are cleaved to 9-unsubstituted acridan and dialkylanilines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 814–816, June, 1975.     

13C NMR spectra of azolopyridines and their quaternary salts

¹³ C NMR spectra of some azole series have been investigated: 2-pyridylbenzimidazoles, 2-pyridylimidazo [4,5-b]-pyridines, 2-pyridylimidazo[4,5-c]-pyridines, analogous oxazole compounds, as well as their mono- and bisquaternary salts. Some problems, related to the structure of these compounds in solution, have been discussed.V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow 117975. Torino University, Italy. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 866–872, April, 1992.     

Preparation of 9-phenylethynyl-4-azafluoren-9-ol and 9-phenacylidene-4-azafluorene and their conversion to spiro compounds

9-Phenylethynyl-4-azafluoren-9-ol, which was obtained from 4-azafluorenone and phenylethynylmagnesium iodide, was used in syntheses of isomeric 9-phenacylidene-4-azafluorenes and spiro compounds with indene, indan, and pyrazoline fragments. It is assumed that the conversion of 9-phenacylidene derivatives to spiro compounds takes place via intramolecular substitution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 510–513, April, 1984.     

Photophysical properties of 3-azafluorenone

Photophysical properties of 3-azafluorenone have been studied in acetonitrile at room temperature (296 K). Its fluorescence quantum yield and fluorescence lifetime were found to be lower than those of fluorenone due to the higher rate of nonradiative processes.     

Reactions of quinazolinium salts with quaternary heterocyclic salts yielding 3-hetarylquinolines

A novel type of transformations of the pyrimidine ring under the action of C-nucleophiles was found and a new method was developed for the synthesis of 3-hetarylquinolines from quinazoline derivatives and quaternary heterocyclic salts. An independent synthesis was carried out and transformations of one of the probable intermediates were studied. By-products were isolated. The effects of the nature of the heterocycle and substituents on the course of the ring transformation reaction were found, and the mechanism of the reaction was suggested. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1210–1215, June, 1998.     

Condensation of 4-azafluorenone and 9-phenacylidene-4-azafluorene with acetophenone. Synthesis of 3′-oxo-spiro-[4-azafluorene-9,1′-indane]

Condensation of 4-azafluorenone and 9-phenacylidene-4-azafluorene with acetophenone leads to the formation of 9,9-diphenacyl-4-azafluorene and 9-(1,2-dibenzoylethylidene)-4-azafluorene. The structures of these products were confirmed based on their spectral and chemical data. The conversion of 9,9-diphenacyl-4-azafluorene to 3-oxo-spiro-[4-azafluorene-9,1-indane] represents a novel method for the preparation of this heterocycle.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1239–1242, September, 1988.     

Effect of micelle formation of quaternary pyridinium salts on their recyclization to anilines

The recyclization of N-alkyl--methylpyridinium salts with an N-alkyl chain consisting of 12 and 16 carbon atoms under the influence of aqueous solutions of sulfites of various amines was studied. It was established that the formation of micellar structures in aqueous solutions of these salts affects the direction of the reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 508–510, April, 1981.     

Thermolysis of quaternary salts of 2-methylbenzothiazole and their methylene bases

The pathways of the thermal transformations of quaternary salts of 2-methylbenzothiazole and their methylene bases were investigated. The schemes of the thermal fragmentation of these compounds are discussed. The possibility of the formation of methylene bases in the thermolysis of quaternary salts of 2-methylbenzothiazole is demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1620–1625, December, 1981.     

Synthesis and structure of quaternary salts of acridinylhetarylmethanes and their anhydro bases

Quaternary salts of 9-acridinylhetarylmethanes were obtained by condensation of acridine with alkiodides of 2- and 4-methyl derivatives of nitrogen heterocycles in the presence of air oxygen. A study of the spectra of the acridinylhetarylmethanes and their quaternary salts and anhydro bases indicates tautomeric transfer of the hydrogen atom of the methylene group to the nitrogen atom of the acridine fragment in monoquaternized acridinylhetarylmethanes.     

Structures of sterically hindered p-hydroxystyrylpyridines and acid-base transformations of their quaternary salts

The structures of p-hydroxystyrylpyridines and a number of their new quaternary salts were studied by means of electronic absorption spectra. The reverse transformation of the salts to the corresponding quinonoid compounds was examined as a function of the pH of the medium, and the equilibrium constants were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1087–1091, August, 1972.     

Alkylbenzonaphthyridinones and benzonaphthyridinium quaternary salts

Four methyl and ethylbenzonaphthyridinones, along with two ethylbenzonaphthyridinium iodides, 2.5-dimethyl-1,5-benzo[c]naphthyridinium iodide, as well as three isomeric N-3-bromopropylbenzonaphthyridinium bromides have been synthesized and their structures confirmed by¹H NMR spectroscopy. Biological data (minimal inhibitory concentrations) for two of the obtained compounds are presented.Institute of Chemistry, Pedagogical University, 42-201 Czestochowa, Poland Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 944–950, July, 2000.     

α-phenylisocinchomeronic and 4-azafluorenone 3-carboxylic acids

3,6-Dimethyl-6-phenylpyridine, obtained on phenylation of 2,5-lutidine, has been used in the synthesis of -phenylisocinchomeronic acid, derivatives of it, and also for the preparation of 4-azafluorenone 3-carboxylic acid. It was established that 4-hydroxy-3,6-dimethyl-2-phenylpyridine was formed on phenylation of 2,5-lutidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 645–648, May, 1986.     

Cyanoethylation of 3-methyl-2-azafluorene

3-Methyl-9,9-di(-cyanoethyl)-2-azafluorene was obtained from 3-methyl-2-azafluorene via the Michael reaction and was converted to the dibasic acid and its diester. Dieckmann condensation of the latter and subsequent hydrolysis gave 3-methyl-4-oxospiro(2-azafluorene-9,1-cyclohexane).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1668–1670, December, 1972.     

Acylation of 3-methyl-2-azafluorene

Acylation of 3-methyl-2-azafluorene under various conditions yielded the enol forms of its (C₍₉₎ acyl derivatives, whereas the ketol form was also isolated in the case of the p-nitrobenzoyl derivative. The character of the compounds formed in the reaction of 3-methyl-2-azafluorene with benzoyl chloride and acetic anhydride is discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–967, July, 1976.