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1.
L. V. Klyba N. A. Nedolya O. A. Tarasova E. R. Sanzheeva 《Russian Journal of Organic Chemistry》2014,50(1):35-44
Fragmentation patterns of 5-methylsulfanyl-1-vinyl-1H-pyrrol-2-amines under electron impact (70 eV) and chemical ionization (methane as reactant gas) were studied for the first time. The electron impact mass spectra of all the examined compounds contained a strong peak of molecular ion which decomposed along four pathways. Two pathways involved cleavage of the C-S bonds with elimination of methyl (major) and MeS radicals (minor), and the two others, decomposition of the pyrrole ring. The chemical ionization mass spectra displayed strong molecular, [M + H]+, and odd-electron [M + H ? SMe]+ ion peaks. N,N-Dimethyl-5-methylsulfanyl-4-phenyl-1-vinyl-1H-pyrrol-2-amine under chemical ionization with methane as reactant gas characteristically decomposed with formation of [M ? C4H9N]+ as the only fragment ion. 相似文献
2.
Klyba L. V. Nedolya N. A. Tarasova O. A. Zhanchipova E. R. 《Russian Journal of Organic Chemistry》2009,45(2):292-303
Russian Journal of Organic Chemistry - Mass spectra of 3,7-di- and 3,6,7-trisubstituted 2-(methylsulfanyl)-4,5-dihydro-3H-azepines were investigated for the first time. The fragmentation of... 相似文献
3.
A synthesis is reported for N1-mono- and N1,N3-disubstituted uracil derivatives containing a terminal carbon-carbon double bond in the side-chain. Alkylation of vinyl 2-chloroethyl ether by uracil potassium salts leads to a mixture of 1-[2-(vinyloxy)ethyl] and 1,3-di[2-(vinyloxy)ethyl] derivatives while treatment of 2,4-bis(trimethylsilyloxy)pyrimidines by vinyl 2-chloroethyl ether leads exclusively to N1-monosubstituted products. Alkylation of cytosine by this chloroether gave 1-[2-(vinyloxy)ethyl]cytosine. The synthesis of 1-[2-(allyloxy)ethyl]uracil derivatives was carried out by treatment of uracil potassium salts by 1-(allyloxy)-2-(p-toluenesulfonyloxy)ethane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 393–397, March, 1993. 相似文献
4.
L. V. Klyba N. A. Nedolya O. A. Tarasova E. R. Zhanchipova O. G. Volostnykh 《Russian Journal of Organic Chemistry》2009,45(4):596-608
The electron impact mass spectra of previously unknown 2-alkyl-6-alkoxy-, 2,3-trimethylene-6-alkoxy- and 2-alkyl-6-aryl(hetaryl)-3H-azepines were studied. All compounds give rise to stable molecular ions (I
rel = 44–100%) whose fragmentation pattern is determined mainly by the substituent on C6. Decomposition of the molecular ions derived from 6-alkoxy derivatives (R1 = MeO, EtO, i-PrO) follows general relations typical of alkyl ethers. The main characteristic peaks in the mass spectra of 2-methyl-6-aryl-
and 2-methyl-6-hetaryl-3H-azepines (R1 = Ph, 1H-pyrrol-1-yl, 5-methylthiophen-2-yl) belong to even-electron rearrangement ions [M − H]+ and [M − Me]+, which have conjugated bi- and tricyclic structures, and products of their subsequent decomposition. Substituents in positions
2 (R2) and 3 (R4) [R4 = H, R2 = Me, Et; R2R4 = (CH2)3] bring some specificity to the fragmentation pattern, but their contribution is not crucial.
Original Russian Text ? L.V. Klyba, N.A. Nedolya, O.A. Tarasova, E.R. Zhanchipova, O.G. Volostnykh, 2009, published in Zhurnal
Organicheskoi Khimii, 2009, Vol. 45, No. 4, pp. 610–621.
For communication VII, see [1]. 相似文献
5.
Nasakin O. E. Kazantseva M. I. Varkentin L. I. Gein V. L. 《Russian Journal of General Chemistry》2018,88(6):1270-1272
Russian Journal of General Chemistry - 1-[2-(1H-indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrole-2(5H)-ones were synthesized by the short heating of a mixture of tryptamine, aromatic... 相似文献
6.
Karoliina Joutsiniemi Pirjo Vainiotalo Olaf Morgenstern Anke Klemann 《Journal of heterocyclic chemistry》1997,34(2):381-384
The spectra of five pharmacologically interesting substituted pyrazolo[1,2-a][1,2,4]triazole hydroiodides were measured under electron and chemical ionization. In the electron ionization spectra, in addition to the intense molecular ion peak of the free base (M+*), there was also a relatively intense molecular ion peak of the hydroiodide form, which is unusual since the hydroiodides are rarely so stable. The phenylimino and phenylamino substituents of the triazole ring affected the fragmentation behaviour of the compounds very much. The chemical ionization reagent gases used in this work were methane, isobutane, deuterated ammonia and acetone. In all the cases practically only [M+H]+ ions were observed, the only exception being acetone which also gave rise to intense [M+C2H3O]+ and [M+C3H7O]+ adduct ions. None of the reagent gases used was able to cause any fragmentation. 相似文献
7.
L. V. Klyba O. A. Tarasova N. A. Nedolya E. R. Sanzheeva 《Russian Journal of Organic Chemistry》2016,52(11):1587-1592
By mass spectrometry methods applying electron ionization (70 eV) and laser desorption/ionization (NALDI, MALDI) 1-(alkyl-, cycloalkyl-, vinyloxyethyl-, and aryl)substituted 2-(alkyl- and propargylsulfanyl)-3-(ferrocenylmethoxy)pyrroles were studied and characterized. At the electron ionization the peak of the molecular ion possesses very low intensity. The main fraction ions are the ferrocenylmethyl ion (the most abundant peak) and its decomposition ions. Under the NALDI conditions molecular ions and protonated molecules [M + H]+ are generated. The general fragmentation rules in the field-free region are determined. By an example of 1-phenyl derivative of pyrrole the MALDI procedure was also demonstrated to be suitable for investigation of 2-(alkylsulfanyl)-3-(ferrocenylmethoxy)pyrroles. 相似文献
8.
The mass spectrometric behaviour of 1-aryl-5-(2-dialkylaminovinyI)-lH-tetrazoles was studied, especially 1-phenyl-5-(2-dimethylaminovinyl)-l H-tetrazole as a typical example of D- and 15N-labelled derivatives revealed a rearrangement via a carbodiimide-like intermediate ion. 相似文献
9.
L. V. Klyba O. A. Tarasova N. A. Nedolya 《Russian Journal of Organic Chemistry》2016,52(12):1773-1778
The electron impact mass spectra of 1-R-substituted 3-alkoxy-2-(propargylsulfanyl)- and 3-alkoxy-2-(allenylsulfanyl)-1H-pyrroles (R = Me, i-Pr, s-Bu, Ph) have been studied for the first time. These compounds give rise to stable molecular ions whose primary fragmentation follows three competing pathways: cleavage of the C–O bonds with expulsion of alkyl radical, cleavage of the C–S bonds with formation of [M–C3H3]+ ions, and cleavage of the C–N bonds with synchronous hydrogen transfer to give odd-electron [M–CnH2n]+ · ion. The main fragmentation pathway of 2-(propargylsulfanyl) derivatives is cleavage of the C–S bond with formation of [M–C3H3]+ ion. 相似文献
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Klyba L. V. Nedolya N. A. Sanzheeva E. R. Tarasova O. A. 《Russian Journal of Organic Chemistry》2021,57(12):1901-1912
Russian Journal of Organic Chemistry - The fragmentation of 5-[(cyanomethyl)sulfanyl]- and 5-[(1,3-dioxolan-2-ylmethyl)sulfanyl]-1H-pyrrol-2-amines under electron impact (70 eV) and chemical... 相似文献
15.
Marina Rentzea Hans-Joachim Hasselbach Heinz A. Staab 《Journal of mass spectrometry : JMS》1986,21(6):367-370
For four isomeric bis(methoxycarbonyl)[2.2](2,5)pyridinophanes differing only in the mutual orientation of the two nicotinic ester units, electron impact mass spectra were measured. The fragmentations observed distinguish surprisingly well between the isomers, depending on the transannular substitution pattern. Of special interest is that for one isomer the otherwise unimportant ion at m/z 298 is found as base peak. This ion is formed by expulsion of HCN from the molecular ion, transannular cycloaddition and aromatization to a stable quinolizinium ion. Fragmentation pathways of the isomers are compared, and chemical ionization and negative ion chemical ionization mass spectra are discussed. 相似文献
16.
L. V. Klyba N. A. Nedolya E. R. Sanzheeva O. A. Tarasova 《Russian Journal of Organic Chemistry》2017,53(6):913-919
Electron impact mass spectra of alkyl 4-alkoxy-5-amino-3-methylthiophene-2-carboxylates were studied for the first time. These compounds, except for 4-(1-ethoxyethoxy) and 4-(ferrocenylmethoxy) derivatives, give rise to a stable molecular ion whose decomposition follows three pathways. The main fragmentation pathway of the molecular ion is elimination of alkyl radical from the 4-alkoxy group, the second pathway involves expulsion of alkoxy group from the ester moiety, and the third pathway is decomposition of the thiophene ring. The molecular ions of 4-(1-ethoxyethoxy)thiophenes decompose mainly via elimination of ethyl vinyl ether molecule with formation of [M–VinOEt]+ · odd-electron ion, and fragmentation of the latter follows general pathways. In the mass spectra of 4-(ferrocenylmethoxy)thiophenes the most abundant are ferrocenylmethyl ion with m/z 199 (I rel 100%) and fragment ions derived therefrom. 相似文献
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David B. Repke Wilfred J. Ferguson Dallas K. Bates 《Journal of heterocyclic chemistry》1977,14(1):71-74
The synthesis of four dialkyl and three eyeloalkyl analogs of psilocin (4, R - CH3), a hallucinogenic principle found in certain fungi, is described. The synthetic route involves four transformations starting with 6,7-dihydroindol-4(5H)one: (1). 相似文献
20.
L. V. Klyba N. A. Nedolya O. A. Tarasova E. R. Zhanchipova O. G. Volostnykh 《Russian Journal of Organic Chemistry》2010,46(2):218-225
Mass spectra were investigated for the first time of four structural isomers of heterocycles, formerly inavailable 7-methyl-2-(methylsulfanyl)-3-(1-ethoxyethoxy)-4,5-dihydro-3H-azepine, 2,2-dimethyl-6-(methylsulfanyl)-5-(1-ethoxyethoxy)-2,3-dihydropyridine, 1-isopropyl-2-(methylsulfanyl)-3-(1-ethoxyethoxy)pyrrole,
and N-isopropyl-N-methyl-3-(1-ethoxyethoxy)-2-thiophenamine prepared from a single linear precursor, adduct of α-lithiated 1-(1-ethoxyethoxy)allene
and isopropyl isothiocyanate. All compounds formed a molecular ion (I
rel
1–6%) whose primary fragmentation at the electron impact (70 eV) occurs in two principal directions related to the cleavage
of the C-O bonds in the 1-ethoxyethoxy-substituent: with a simple rupture of the bonds C-OEt and C-O(heterocycle) and with
the elimination of an ethoxyethene molecule. In the spectra of 4,5-dihydro-3H-azepine and 2,3-dihydropyridine the first fragmentation
channel of [M]+· dominates. The second direction prevailes at the fragmentation of pyrrole and thiophene molecular ions leading to an odd-electrons
ion with m/z 171. Further fragmentation of this ion is characteristic of each isomer and resulted in the formation of diagnostic
ions providing a possibility of identification of these isomers by mass spectrometry. 相似文献