Mass spectrometry of diazo compounds

Lebedev, A. T.

doi:10.1002/mas.1280100202

Cited by 31 publications

(24 citation statements)

References 63 publications

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“…The cyclization products of the molecular ions for these benzamides were identical to those synthesized in the condensed phase [4,5]. In the present study, we continue research in this area, investigating the possibility of rearrangements of substituted N-(ortho-cyclopropylphenyl)-N=-aryl ureas (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14).) and N-(ortho-cyclopropylphenyl)-N=-aryl thioureas (15)(16)(17)(18)(19)(20)(21)(22)(23), structurally related to the earlier studied acetamides [6] and benzamides [4,5].…”

mentioning

confidence: 65%

“…Mass spectrometry allows for the prediction of monomolecular reactions of the substituted N-(orthocyclopropylphenyl)-N=-aryl ureas (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) and N-(orthocyclopropylphenyl)-N=-arylthioureas (15-23) catalyzed by acids in solution. Two model compounds, (1 and 15), were subjected to the acid catalyzed cyclization.…”

Section: Discussionmentioning

confidence: 99%

“…M ass spectrometry has been proven to be a powerful, rapid method for the prediction of the direction and yields of monomolecular reactions of organic compounds in solution [1]. Previously, we successfully used mass spectrometry to study cyclization of various diazo compounds [2] and orthosubstituted phenylcyclopropanes [3]. The spectral conclusions for a representative series of N-(ortho-cyclopropylphenyl)benzamides were used to confirm the presence of the predicted heterocycles in solution.…”

mentioning

confidence: 99%

“…Previously, we successfully used mass spectrometry to study cyclization of various diazo compounds [2] and orthosubstituted phenylcyclopropanes [3]. The spectral conclusions for a representative series of N-(ortho-cyclopropylphenyl)benzamides were used to confirm the presence of the predicted heterocycles in solution.…”

mentioning

confidence: 99%

“…Substituted N-(ortho-cyclopropylphenyl)-N=-aryl ureas (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) and N-(ortho-cyclopropylphenyl)-N=-aryl thioureas (15)(16)(17)(18)(19)(20)(21)(22)(23) possess four nucleophilic sites [N, N=, O (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) or S (15)(16)(17)(18)(19)(20)(21)(22)(23), and the ortho-position of the aromatic ring attached to N=], which are able to attack the charged cyclopropyl moiety. Therefore, at least four heterocycles (P 1 -P 4 ) can be formed in the intramolecular cyclization reaction.…”

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confidence: 99%

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Cyclization of the substituted N-(Ortho-cyclopropylphenyl)-N′-aryl ureas and thioureas in the gas phase and solution

Lobodin

Федотов

Dem’yanov

et al. 2005

J. Am. Soc. Mass Spectrom.

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Electron ionization (EI), chemical ionization (CI), tandem mass spectrometry, high-resolution measurements, and labeling studies as well as quantum chemical calculations were used to understand the behavior of the molecular radical cations (EI) and protonated molecules (CI) of substituted N-(ortho-cyclopropylphenyl)- N=-aryl ureas and N-(ortho-cyclopropylphenyl)-N=-aryl thioureas in a mass spectrometer. Fragmentation schemes and possible mechanisms of primary isomerization were proposed. According to the fragmentation pattern, formation of the corresponding benzoxazines and benzothiazines was considered as the major process of isomerization of the original M ϩ· and MH ϩ , although some portions of these ions definitely transformed into other structures. M ass spectrometry has been proven to be a powerful, rapid method for the prediction of the direction and yields of monomolecular reactions of organic compounds in solution [1]. Previously, we successfully used mass spectrometry to study cyclization of various diazo compounds [2] and orthosubstituted phenylcyclopropanes [3]. The spectral conclusions for a representative series of N-(ortho-cyclopropylphenyl)benzamides were used to confirm the presence of the predicted heterocycles in solution. The cyclization products of the molecular ions for these benzamides were identical to those synthesized in the condensed phase [4,5]. In the present study, we continue research in this area, investigating the possibility of rearrangements of substituted N-(ortho-cyclopropylphenyl)-N=-aryl ureas (1-14).) and N-(ortho-cyclopropylphenyl)- N=-aryl thioureas (15-23), structurally related to the earlier studied acetamides [6] and benzamides [4,5]. These compounds were expected to undergo EI induced and acid catalyzed cyclization in a similar manner.Substituted N-(ortho-cyclopropylphenyl)- N=-aryl ureas (1-14) and N-(ortho-cyclopropylphenyl)-N=-aryl thioureas (15-23) possess four nucleophilic sites [N, N=, O (1-14) or S (15-23), and the ortho-position of the aromatic ring attached to N=], which are able to attack the charged cyclopropyl moiety. Therefore, at least four heterocycles (P 1 -P 4 ) can be formed in the intramolecular cyclization reaction.

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confidence: 65%

Section: Discussionmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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Cyclization of the substituted N-(Ortho-cyclopropylphenyl)-N′-aryl ureas and thioureas in the gas phase and solution

Lobodin

Федотов

Dem’yanov

et al. 2005

J. Am. Soc. Mass Spectrom.

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ChemInform Abstract: Mass Spectrometry of Diazo Compounds

Lebedev

1991

ChemInform

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A critical evaluation of the application of capillary electrophoresis to the detection and determination of 1,4‐benzodiazepine tranquilizers in formulations and body materials

Smyth¹,

McClean²

1998

Electrophoresis

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Studies of the capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) behaviour of 1,4-benzodiazepines have seen application in subject areas such as the development of pharmaceuticals, therapeutic drug monitoring and forensic toxicology. In the development of pharmaceuticals, pKa determinations by CZE can be used in preclinical studies whereas analytical data on the detection and determination of 1,4-benzodiazepines is of value primarily in raw material/formulation assay and in the analysis of body fluids in clinical studies. The capillary electrophoresis (CE) techniques, which generally have inferior limits of detection (LOD) to rival techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC), are particularly applicable in forensic toxicology where reasonably high concentrations of these drugs can be encountered. It is anticipated that, with the interfacing of CZE and capillary electrochromatography (CEC) with mass spectrometry (MS) techniques, the excellent selectivity of CZE and particularly CEC will be effectively combined with the sensitivity of MS and the identification capabilities of tandem mass spectrometry (MS/MS) and MS hyphenated (MSn) techniques.

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Mass spectrometry of diazo compounds

Cited by 31 publications

References 63 publications

Cyclization of the substituted N-(Ortho-cyclopropylphenyl)-N′-aryl ureas and thioureas in the gas phase and solution

Cyclization of the substituted N-(Ortho-cyclopropylphenyl)-N′-aryl ureas and thioureas in the gas phase and solution

ChemInform Abstract: Mass Spectrometry of Diazo Compounds

A critical evaluation of the application of capillary electrophoresis to the detection and determination of 1,4‐benzodiazepine tranquilizers in formulations and body materials

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