Mass-spectrometric study of adamantane derivatives

Conclusions The characteristic features of the mass spectra of a number of monofunctional alkyladamantanes, substituted in junction points, were found.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1028–1030, May, 1972.     

Mass-spectrometric study of 2- and 4-thiobarbituric acid derivatives

The mass spectra of 2- and 4-thiobarbituric acids and some of their close analogs at ionizing voltages of 70 and 14 eV are compared. Qualitative and quantitative differences in the behavior of these compounds under the influence of electron impact were established. It is shown that the position of the thione group in the ring and the tautomeric transformations have a substantial effect on the character of the fragmentation of the investigated compounds. The established fragmentation principles make it possible to distinguish the structural isomers in a series of 2- and 4-thiobarbituric acids from their mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 529–535, April, 1976.     

Mass-spectrometric study of sulfenamide derivatives of 2-substituted benzothiazoles

It is shown that the dissociative ionization of 2-mercaptobenzothiazole derivatives with a sulfenamide bond is accompanied by cleavage of the labile N-S bond and simultaneous migration of the hydrogen atom from the thiol substituent at the site of cleavage to the sulfur atom. Ion peaks with mass 167, 166, R, and (R-H), where R is an N-substituted cycloalkylamine, are maximum peaks and are used for the identification of the compounds.Translated from Khimiya Geterotsiklicheskikh Soedmenii, No. 10, pp. 1330–1336, October, 1975.     

Mass-spectrometric study of some derivatives of furo- and dihydrofurocoumarins

Summary The mass spectra of eight compounds beloning to the class of linear furo- and dihydrofurocoumarins have been studied. A scheme of the fragmentation of these substances under the action of electron impact has been proposed. It has been shown that the mass-spectrometric method permits acyl derivatives of oreoselone to be distinguished reliably from acyl derivatives of dihydrooreoselol and the latter series of substances from derivatives isomeric with them belonging to the class of dihydrofuro- and dihydropyranocoumarins.M. V. Lomonsov Moscow State University. All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 560–568, September–October, 1974.     

Mass-spectrometric study of nitro derivatives of 2(4)-azafluorenes and 2(4)-azafluorenones

The dissociative ionization of 13 nitro derivatives of 2(4)-azafluorenes and 2(4)-azafluorenones was investigated. The introduction of an electron-acceptor nitro group into the molecule markedly reduces the stability of the molecular ions and suppresses the fragmentation pathways that are characteristic for azafluorenes. Nitro-nitrite rearrangement proceeds more readily in nitro-substituted 4-azafluorenes than in nitro-substituted 2-azafluorenes. A characteristic feature of the fragmentation of azafluorenes that do not contain nitro and methyl groups in a vicinal orientation is elimination of a OH particle by the molecular ions. It was established by deuterium labeling that in this case the formation of an [M — OH]⁺ ion is due to the presence of a methylene group attached to the C₉ atom in the molecule.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 941–947, July, 1981.     

Mass-spectrometric study of substituted tetrahydro-4-thiopyrones

The mass spectra of 16 methyl- and phenyl-substituted tetrahydro-4-thiopyrones that differ with respect to the position of the substituents in the ring and some of their deutero derivatives were studied. The principal pathways of dissociative ionization of these compounds are due to cleavage of the a bonds with respect to the heteroatom and the carbonyl group. Analytical features that make it possible to determine the position of the substituents in the tetrahydro-4-thiopyrone ring and distinguish the structural and spatial isomers in this series of compounds were found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 619–626, May, 1981.     

Mass-spectrometric study of phenothiasilines and of their derivatives and analogs

Conclusions A study was made of some phenothiasiline derivatives and analogs and the main paths of their fragmentation were established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1619–1622, July, 1981.     

Mass-spectrometric study of the sesquiterpene lactone germanin-A and its derivatives

Summary The mass spectra of the sesquiterpene lactone germanin-A and 11 of its derivatives and deuterium analogs have been studied. A scheme has been put forward for the decomposition of germanin-A under the action of electron impact. It has been established that the elimination of a molecule of acid from position 8 in the dissociative ionization of germanin-A and of tetrahydrogermanin-A involves the hydrogen atom of the carboxy group present in position 10 of the sesquiterpene ring. On this basis, a suggested conformation of the germanin-A molecule has been put forward.M. V. Lomonosov Moscow State University. All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–345, May–June, 1978.     

Mass-spectrometric study of adamantane derivatives (diadamantyls and diadamantylethanes)

Conclusions Characteristic differences were found to exist between the mass spectra of the isomeric compounds of the diadamantyl and diadamantylethane series.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 439–414, February, 1971.     

Mass-spectrometric study of the sesquiterpene lactone grossmisin and its derivatives

Summary The dissociative ionization of grossmisin [O–D]grossmisin, and two of its derivatives have been studied. The appearance of the main fragments in the mass spectrum of grossmisin is due to the elimination by the M⁺ ion of H₂O and CO molecules and CH₃ and OH radicals in various sequences. The hypothesis has been put forward that in the splitting off of a CH₃COOH molecule by the M^+° ion of acetylgrossmisin a rearrangement of the lactone ring takes place with its reclosure at the C₆ carbon atom of the seven-membered ring.M. V. Lomonosov Moscow State University. Patrice Lumumba International Friendship University, Moscow. All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 344–349, May–June, 1977.     

Mass-spectrometric study of 2- and 4-azafluorenones

A mass-spectrometric study of 2- and 4-azafluorenones and their mono- and polymethyl derivatives showed that the presence of a methyl group in the benzene ring leads to a sharp increase in the relative intensity of the [M — H]⁺ ion peak. In contrast to the fragmentation of 2- and 4-azafluorenes, the mass spectra of monomethyl-substituted compounds do not contain an [M — CH₃]⁺ fragment; this is probably associated with expansion of the pyridine or benzene ring to a seven-membered ring in the step involving the formation of the molecular ion due to inclusion of the methyl group. The intensity of the [M — CO]⁺ ion peak in the mass spectra of the 4-azafluorenones is higher by a factor of two with respect to the 2-azafluorenone isomers, and the [M — HCN]⁺ and [M — H, -HCN]⁺ ion peaks observed in the mass spectra of 2-azafluorenones are absent in them.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 89–95, January, 1979.     

Mass-spectrometric investigation of some indole derivatives

The mass spectra of 5-hydroxytryptophan, 5-hydroxytryptamine, 5-methoxy-N-methyltryptamine, 5-hydroxydimethyltryptamine, 5-hydroxyindolylacetic acid, and 5-methoxytryptamine are examined. Schemes for the disintegration of the molecular ions are given.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1357–1358, October, 1973.     

Mass-spectrometric fragmentation of phosphorylated anabasine derivatives

The mass-spectrometric fragmentation of hexyl anabasinoisopropyl, and isoamyl anabasinobut-2-ynyl phenylphosphonates has been investigated. Schemes for the fragmentation of the substances are given.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 75–77, January–February, 1994.     

Mass-spectrometric study of substituted 4-alkyldecahydro-4-quinolols and decahydro-4-quinolones

The primary fraction of the total ion current in the mass spectra of decahydro-4-quinolones and 4-alkyl-2-methyldecahydro-4-quinolols containing various substituents in the 1, 4, and 7 positions is due to fragments with ammonium ion structures.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 962–968, July, 1975.     

Mass-spectrometric study of methyl-substituted azomethines of the 4-azafluorene series

The M⁺ and [M-H]⁺ ion peaks are the peaks of maximum intensity in the mass spectra of Schiff bases belonging to the 4-aza-9-fluorenylidenearylamine series. The dependence of the relative intensity of the [M-H]⁺ fragment on the structures of the I–XI molecules provides evidence for the possibility of the occurrence of rearrangement processes involving the formation of this ion. The formation of [M-CH₃]⁺, [M-HCN]⁺, [M-Ar]⁺, and [M-CNAr]⁺ ions is also characteristic for the fragmentation of the investigated compounds. It was found that, in contrast to other types of Schiff bases, the ejection of an HCN molecule during the mass-spectrometric fragmentation of the investigated compounds occurs without participation of the nitrogen atom of the azomethine group. The elimination of a CNAr particle by the molecular ions is a distinctive feature of the investigated series of Schiff bases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 397–402, March, 1979.