Electron impact studies on some aryl heteryl ketoximes

Kallury, R. Krishna Mohan Rao; Rao, P. L. K. M.

doi:10.1002/oms.1210120614

Cited by 21 publications

(4 citation statements)

References 13 publications

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“…High-resolution El mass spectra were obtained to ensure that even traces (<1%) were not present. The loss of an oxygen atom upon El was reported for some oximes and oxime O-alkyl ethers (35)(36)(37)(38)(39)(40) and was at first considered an unusual mass spectrometric fragmentation (35)(36)(37). Later it was explained as a thermal decomposition process (38)(39)(40), in agreement with the known fact that when oximes are subjected to intense heating, they can decompose to the corresponding imines (41).…”

Section: Resultsmentioning

confidence: 59%

“…The loss of an oxygen atom upon El was reported for some oximes and oxime O-alkyl ethers (35)(36)(37)(38)(39)(40) and was at first considered an unusual mass spectrometric fragmentation (35)(36)(37). Later it was explained as a thermal decomposition process (38)(39)(40), in agreement with the known fact that when oximes are subjected to intense heating, they can decompose to the corresponding imines (41). One source for the [M -0]+ ion formation under El conditions, other than a thermal reaction, was proposed to be the bimolecular reaction 2[M]+* -[ -0]+ + [ + 0]+ (42).…”

Section: Resultsmentioning

confidence: 59%

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Fast-atom-bombardment-induced reduction of aromatic oximes

Santana-Marques¹,

Ferrer‐Correia²,

Gross³

1989

Anal. Chem.

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Aromatic oximes and /?-hydroxyoxlmes are reduced to their corresponding Imines by Interaction of their solutions In glycerol solvent with a 7-keV argon atom beam. Evidence that the reduction occurs for the protonated oximes comes from fast atom bombardment (FAB) mass spectrometry, tandem mass spectrometry, and time-resolved FAB studies. The requirement that the oxime be In solution was established by comparing the FAB results with those obtained by electron Ionization, chemical Ionization, and laser desorption. The time-dependent studies of the concentration of the protonated oxime and the reduced product, a protonated Imlne, were made with and without added anionic surfactant. The abundance of the reduced species depends on the concentration of the protonated oxime at the matrix surface, thus showing that the first step of the reduction mechanism Is the protonation of the analyte, followed by reduction and eventual desorption of the reduced species. Surface reduction occurs for all the compounds containing an oxime group that were studied and Is a useful characteristic for Identifying oximes by fast atom bombardment mass spectrometry.

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Section: Resultsmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 59%

Fast-atom-bombardment-induced reduction of aromatic oximes

Santana-Marques¹,

Ferrer‐Correia²,

Gross³

1989

Anal. Chem.

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“…The EI spectra of oximes [1][2][3][4][5] The EI spectra of oximes 1-5 are listed in Table 1 and the major fragmentation pathways are summarized in Scheme 1. The molecular ions are insignificant in all the oximes because further decomposition occurs.…”

Section: Resultsmentioning

confidence: 99%

Electron impact and chemical ionization mass spectra of 2,2‐diphenyl‐3‐arylcyclobutanone oximes. Formation of ion m/z 167

Reddy

Smith

1986

Org. Mass Spectrom.

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The electron impact (EI) and chemical ionization (CI) spectra of 2,2-diphenyl-3-aryl cyclobutanone oximes (1-5) are reported. Formation of diphenylmethyl cation at m / z 167 is a major fragmentation process in both EI and CI spectra. Labelling studies established that the hydrogen involved in this rearrangement transfers from the NOH group and not from cyclobutane ring positions. The [M + 31" ions are formed under CI conditions as a result of C=N double bond reduction. An interesting secondary kinetic isotope effect is observed in the formation of ion e at m / z 183 in both EI and CI spectra. Other characteristic fragmentation pathways occurring in the EI and CI spectra of these compounds are outlined.

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“…The acylfurans thus obtained reacted with hydroxylamine to give the oximes (1)(2)(3)(4)(5)(6)(7)(8). 16 The compounds 9 and 10 were the products of the reaction of ethyl Iurfurylcarboxylate and the corresponding amines at 25°Cand then purified by vacuum distillation.…”

Section: Methodsmentioning

confidence: 99%

Mass Spectra of Furfuryl Aldoximes and Ketoximes

Lin

Kuo

Lin

1991

J Chinese Chemical Soc

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The mass spectra of 8 furfuryl aldoximes and ketoximes were studied under EI and CI conditions. Complicated fragmentation patterns were obtained in EI conditions, including formation of a furfuryl cation radical, furfuryl cation, and [M‐17]+. The relatively simple patterns of cleavage resulted in few major ion peaks contributed from the adducts, protonation products, and dehydration products under CH4‐CI and NH3‐CI conditions. Comparison with the spectra of their isomeric amides indicated no evidence that the isomerization took place from oximes before fragmentation in both ionization methods.

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Electron impact studies on some aryl heteryl ketoximes

Cited by 21 publications

References 13 publications

Fast-atom-bombardment-induced reduction of aromatic oximes

Fast-atom-bombardment-induced reduction of aromatic oximes

Electron impact and chemical ionization mass spectra of 2,2‐diphenyl‐3‐arylcyclobutanone oximes. Formation of ion m/z 167

Mass Spectra of Furfuryl Aldoximes and Ketoximes

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