Mass spectral studies of <i>N,N</i>‐dialkylaminoethanols

Reddy, T. Jagadeshwar; Mirza, Shama P.; Saradhi, U.V.R. Vijaya; Rao, V. Jayathirtha; Vairamani, M.

doi:10.1002/rcm.962

Cited by 25 publications

(25 citation statements)

References 18 publications

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“…The last structure on the right side represents a possible isomeric structure published elsewhere. 22 Similar fragmentation takes place in the case of PPOH and PPCl derivatives, where the results were also confirmed with deuterated analogs. Figure 5 describes the part of main fragmentation pathway of P d7 POH after elimination of water.…”

Section: Minor Fragmentation Processessupporting

confidence: 72%

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Mass spectrometric study of selected precursors and degradation products of chemical warfare agents

et al. 2007

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Selected precursors and degradation products of chemical warfare agents namely N,N-dialkylaminoethane-2-ols, N,N-dialkylaminoethyl-2-chlorides and some of related N-quaternary salts were studied by means of electrospray ionization-multiple tandem mass spectrometry (ESI-MS(n)). Proposed structures were confirmed with accurate mass measurement. General fragmentation patterns of these compounds are discussed in detail and suggested processes are confirmed using deuterated standards. The typical processes are elimination of alkene, hydrogen chloride, or water, respectively. Besides, elimination of ethene from propyl chain under specific conditions was observed and unambiguously confirmed using exact mass measurement and labelled standard. The potential of mass spectrometry to distinguish the positional isomers occurring among the studied compounds is reviewed in detail using two different MS instruments (i.e. ion trap and hybrid quadrupole-time of flight (Q-TOF) analyzer). A new microcolumn liquid chromatography (microLC)/MS(n) method was designed for the cases where the resolution based solely on differences in fragmentation is not sufficient. Low retention of the derivatives on reversed phase (RP) was overcome by using addition of less typical ion pairing agent (1 mM/l, 3,5-dinitrobenzoic acid) to the mobile phase (mixture water : acetonitrile).

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Section: Minor Fragmentation Processessupporting

confidence: 72%

“…According to the sug- with 100-fold higher abundance than its fragments was determined with accuracy of 3.3 ppm. Reddy et al 22 studied fragmentation of some of N,N-dialkyl aminoethanols using triple quadrupol MS analyzer. During the fragmentation of N,N-dipropyl derivative the ion m/z 86 was also observed.…”

Section: Minor Fragmentation Processesmentioning

confidence: 99%

Mass spectrometric study of selected precursors and degradation products of chemical warfare agents

et al. 2007

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“…The relative abundance of ion k is higher than that of ion j, except in Compound 5 wherein the ion j is the base peak in the spectrum. All the compounds containing higher alkyl groups [R Ͼ CH 3 ] on nitrogen show the ␤-cleavage [15] fragment ion (l) as the base peak. Further elimination of CH 2 O from the ion l by the McLafferty type rearrangement leading to ion m is characteristically found in all the compounds (6-9) (Scheme 4).…”

Section: Oo-dimethyl Nn-dialkyl Phosphoramidates (Series 2)mentioning

confidence: 99%

“…Capillary column gas chromatographs equipped with mass selective detectors (GC/ MSD) in EI and chemical ionization (CI) modes are widely used for the unambiguous identification of compounds present in different environmental matrices [2][3][4][5][6][7][8][9][10][11][12][13][14]. Recently, we reported the mass spectral analysis of N,N-dialkyl aminoethanols that are precursors for various nitrogen mustards and nerve agents (VX) [15]. The EI mass spectra of diethyl and dimethyl N,Nmethylphosphoramidates are reported in literature [3,10] and the EI mass spectra for some of the phosphoramidates are available in the OPCW and other commercial mass spectral library databases.…”

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confidence: 99%

Mass spectral study on O,O-dialkyl N,N-dialkyl phosphoramidates under electron impact conditions

Reddy

Prabhakar

Saradhi

et al. 2004

J. Am. Soc. Mass Spectrom.

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A series of O,O-dialkyl N,N-dialkyl phosphoramidates (1-25) were analyzed under GC-EIMS conditions. Clear-cut differences are found in the fragmentation of O,O-dialkyl N,N-dimethyl phosphoramidates (Series 1) and O,O-dimethyl N,N-dialkyl phosphoramidates (Series 2). The phosphoramidates comprising of mixed/crossed alkyl groups on nitrogen and oxygen (Series 3) showed mixed fragmentation pattern corresponding to both Series 1 and 2 depending on the nature of alkyl groups. All the possible isomers among the studied compounds showed distinguishable EI mass spectra. Although the major ions in the EI mass spectra for the isomers containing O-n-propyl or O-isopropyl and N,N-diethyl or N-isopropyl N-methyl are similar, the isomers could be distinguished by characteristic ions of low abundance at low mass region. The differences are prominent in the metastable ion spectra of characteristic ions. (J Am Soc Mass Spectrom 2004, 15, 547-557)

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“…Since gas chromatography coupled with mass spectrometry (GC/MS) is the widely used technique for identification of CWC-related chemicals, [19][20][21][22] a great deal of work is devoted to developing the mass spectral database for these compounds. [23][24][25][26] The important synthones of nerve agents are N,Ndialkylphosphoramidic dihalides and alkylphosphonyl difluorides 2,27 (Fig. 1), which are placed in the CWC as schedule 2.B.5.…”

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confidence: 99%

Mass spectral analysis of synthones of nerve agents for verification of the Chemical Weapons Convention

Gupta

Shakya

Pardasani

et al. 2005

Rapid Comm Mass Spectrometry

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This communication describes the synthesis and gas chromatography/mass spectrometric (GC/MS) analysis of N,N-dialkylphosphoramidic dihalides and alkylphosphonic difluorides, which are synthones of nerve agents. The study was undertaken with a view to developing a spectral database of these compounds for verification purposes of the Chemical Weapons Convention (CWC). The modified synthetic approach reported here has advantages over traditional syntheses in terms of time and yield. GC/MS analysis of these synthones yielded electron ionization (EI) mass spectra and, based on these spectra, generalized fragmentation routes are proposed that rationalize most of the characteristic ions.

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Mass spectral studies of N,N‐dialkylaminoethanols

Cited by 25 publications

References 18 publications

Mass spectrometric study of selected precursors and degradation products of chemical warfare agents

Mass spectrometric study of selected precursors and degradation products of chemical warfare agents

Mass spectral study on O,O-dialkyl N,N-dialkyl phosphoramidates under electron impact conditions

Mass spectral analysis of synthones of nerve agents for verification of the Chemical Weapons Convention

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