Mass spectrometric study of 4-azafluorenes

The dissociative ionization of 4-azafluorene and its methyl and phenyl derivatives was investigated. The relative intensity of the [M — CH₃]⁺ ion peak depends on the position of the CH₃ group in the 4-azafluorene ring. It was established that the loss of an RCN particle (R=H, CH₃, and C₆H₅) for unsubstituted 4-azafluorene takes place from the M⁺ and [M — H]⁺ ion, exclusively from the [M — H]⁺ ion for the methyl-substituted compounds, and from the [M — H]⁺ and [H — 2H]⁺ fragments for the phenyl-substituted derivatives. Randomization of the deuterium ions in the 9,9-d₂-4-azafluorene molecular ion was observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–250, February, 1978.     

Electronic structures and electrophilic substitution in 2-(4-R-2-quinolyl)thiophenes and 5-(4-R-2-quinolyl)-2,2′-dithienyls

The electronic structures and reactivity indexes (RI) of 2-(4-R-2-quinolyl)thiophenes and 5-(4-R-2-quinolyl)-2,2-dithienyls (R = H, COOH, COOC₂H₅, and NHCOCH₃) and their protonated forms were calculated by the Pariser-Parr-Pople (PPP) method. The peculiarities of the geometrical and -electron structures were established. The calculated reactivity indexes are compared with experimental data on the electrophilic substitution reactions of the investigated compounds. A qualitative agreement between the calculated values and the experimental data was established. It is shown that quinoline derivatives of thiophene are less reactive than the corresponding dithienyl compounds in electrophilic substitution reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 751–754, June, 1979.     

Schiff bases in syntheses of substituted naphthylamines,naphthyridines, azaphenanthrenes,and benzocarbazole

9-Methylnaphtho[2,1-b][1,6]naphthyrldine and 2,3-dimethyl-1-azaphenanthrene were obtained on a K-16 dehydrogenating catalyst from N-(1,2,5-trimethyl-4-piperidylidene)--naphthylamine, while N-cyclohexylidene--naphthylamine yielded N-phenyl--naphthylamine and benzo[a]carbazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1400–1403, October, 1972.     

PMR spectra of azacinnolines

An analysis of the PMR spectra (using double resonance) of the isomeric 3-, 6-, 7-, and 8-methyl and 7-ethyl-5-azacinnolines, and also of 7-methyl-8-azacinno-line has shown the presence in these structures of a considerable localization of the C₅-C₆ and C₇-C₈ bonds, which has been confirmed by the results of a quantum-chemical calculation by the PPP method.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 541–543, April, 1980.     

Indolopyridines with a bridging heteroatom

Reaction of 2-acetylpyridine with 4-[2.2]paracyclophanyllithium or 4-acetyl[2.2]paracyclophane with 2-pyridllithium gives 1-([2.2]paracyclophan-4-yl)-1-(2-pyridyl)ethanol. Its molecular and crystalline structures have been studied by x-ray analysis. It was found that heating this alcohol in acid medium causes dehydration and heterocyclization to give 1-paracyclophanyl-1-pyridylethylene and 10-methyl[2.2]paracyclophano[4,5-bindolizine.For communication 9 see [1]. This report is also communication [5] in the series Synthesis, Structure, and Biological Activity of [2.2]Paracyclophanes (for communication 4 see [2]).Russian University of National Friendship, Moscow 117198. A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, Moscow 117813. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 793–800, June, 1997.     

Vibronic properties of 2-azaanthracene and its derivatives

We report an experimental and theoretical (PPP method) study of the UV absorption spectra of 2-azaanthracene and four of its methyl-substituted derivatives. We find that the p bands of these compounds consist of two different vibronic ^* bands. Our experimental and theoretical results suggest a rule for evaluating the effect of methyl groups on ^* transition energies as a function of the charge on the atoms. We interpret the reasons for the different effects of a polar solvent and hydrogen bonding on the ^* bands of these compounds.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 7–15, June, 1977.     

Cathodic synthesis of esters of 1,1,2,2-cycloalkanetetracarboxylic acids derived from 1,1,2,2-ethane- or ethylenecarboxylate esters

The cathodic electrolysis of esters of 1,1,2,2-ethane- or ethylenetetracarboxylic acids in the presence of dihaloalkanes leads to esters of 1,1,2,2-cycloalkanetetracarboxylic acids.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 217–220, January, 1992.     

1,3-diphenyl-2-azaanthracene and 8-aza-7-phenylbenzo[a]fluoranthene in the diene synthesis

The diene condensation of 1,3-diphenyl-2-azaanthracene with maleic anhydride proceeds under more severe conditions than the analogous condensation with anthracene. On the basis of an analysis of the PMR data for the adduct obtained it was assumed that isomers of ,-[9,10-dihydro-2-aza-1,3-diphenylanthrylene(9,10)]succinic anhydride with respect to the position of the anhydride bridge relative to the pyridine ring are formed in this condensation. 9,10-Dihydro-2-aza-1,3-diphenyl-9, 10-(1-cyanoethylene)anthracene was obtained in the condensation of the same azaanthracene with acrylonitrile. ,-[5H-8-Aza-7-phenylbenzo[a]fluoranthrylene (5,12b) ]succinic anhydride is formed as a result of the similar condensation of 8-aza-7-phenylbenzo[a]fluoranthene with maleic anhydride, while isomeric (with respect to the position of the nitrile group in the ethylene bridge) 5H-8-aza-7-phenyl-5,12b-(cyanoethylene)benzo[a]fluoranthenes were isolated in its condensation with the acrylonitrile. Data from the PMR and IR spectra were used to prove the structures of the adducts of the diene synthesis obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1647, December, 1980.     

Nitration of some 2, 5-disubstituted 4-phenylpyridin es

2,5-Dimethyl-4-phenylpyridine is nitrated in the para position of the phenyl ring. Further nitration of the resulting nitro compound gives a mixture of isomeric dinitro derivatives. In the case of 4-phenylisocinchomeronic acid the nitro group enters the meta position of the phenyl ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 3, pp. 365–368, March, 1976.     

Reactions of 2, 5-dimethyl-4-triphenylsilylpyridine at the α-methyl group

5-Methyl-4-triphenylsilylpyridine-2-carboxylic acid was synthesized, esterified, and decarboxylated. Several transformations of trans-5-methyl-4-triphenylsilyl-2-styrylpyridine were examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 957–961, July, 1972.