Mass Spectrometry of N-Benzoyl-2-hydroxyalkylamines. Role of the Hydroxylic Hydrogen in the Fragmentation Pattern

1975 ◽  
Vol 53 (21) ◽  
pp. 3175-3187 ◽  
Author(s):  
Don C. DeJongh ◽  
Denis C. K. Lin ◽  
Pierre LeClair-Lanteigne ◽  
Denis Gravel
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Relative Importance ◽  
Hydrogen Atoms ◽  
Related Compounds ◽  
Double Hydrogen ◽  
Hydrogen Rearrangement

An interesting rearrangement has been observed in the mass spectra of a series of N-benzoyl-2-hydroxyalkylamines. The hydrogen atom of the hydroxyl group is transferred to the N-benzoyl portion of the molecular ion and the bond between positions 1 and 2 in the N-alkyl group is cleaved. A rearrangement ion, observed at m/e 135, is formed along with a neutral aldehyde or ketone. When the hydroxylic hydrogen is replaced by a trimethylsilyl substituent, the latter group is transferred with comparable efficiency. Differences in the relative importance of this rearrangement in the mass spectra of a series of related compounds with decreasing substitution at position 2, have been explained by differences in the stabilities of the neutral molecules formed along with m/e 135 and by the occurrence of a double hydrogen rearrangement which competes if hydrogen atoms are present in a relationship gamma and delta to the carbonyl group.

ChemInform Abstract: MASS SPECTROMETRY OF N-BENZOYL-2-HYDROXYALKYLAMINES. ROLE OF THE HYDROXYLIC HYDROGEN IN THE FRAGMENTATION PATTERN

1976 ◽  
Vol 7 (10) ◽  
pp. no-no
Author(s):  
DON C. DEJONGH ◽  
DENIS C. K. LIN ◽  
PIERRE LECLAIR-LANTEIGNE ◽  
DENIS GRAVEL
Keyword(s):  
Mass Spectrometry ◽  
Fragmentation Pattern

Derivatization in Mass Spectrometry—1. Silylation

2003 ◽  
Vol 9 (1) ◽  
pp. 1-21 ◽  
Author(s):  
John M. Halket ◽  
Vladimir G. Zaikin
Keyword(s):  
Mass Spectrometry ◽  
Structure Determination ◽  
Spectral Properties ◽  
Mass Spectra ◽  
Biologically Active ◽  
Chromatographic Mobility ◽  
Mass Spectral ◽  
Silyl Derivatives ◽  
Catalytic Stability

This is the first of a series of reviews on the application of derivatization in mass spectrometry. A description is given of advances in silylation as a powerful tool used for increasing the volatility, thermal and thermo-catalytic stability, and chromatographic mobility of polar and unstable organic compounds. In addition to chemical aspects of silylation, mass spectral properties of silyl derivatives useful for structure determination and quantitation of various organic and biologically-active compounds, mainly by GC/MS, are described. Practically all tested and widely used silylating agents are described. The role of comprehensive libraries containing reference mass spectra for various silyl derivatives and search systems in structure determination is emphasized. Applications of silylation for particular analyses are summarised.

Mass Spectrometry of some Nuclear Substituted Styryl Ketones

1972 ◽  
Vol 50 (6) ◽  
pp. 871-879 ◽  
Author(s):  
P. J. Smith ◽  
J. R. Dimmock ◽  
W. G. Taylor
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Aromatic Substitution ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
Aliphatic Ketones ◽  
Decomposition Processes ◽  
Structure Formula ◽  
Related Compounds ◽  
Carbonyl Function

The mass spectra of a series of nuclear substituted styryl ketones with the structure[Formula: see text]and several relaTed compounds have been determined. The major fragmentation pathways include such processes as an aromatic substitution reaction occurring in the molecular ion as well as the McLafferty rearrangement. Only one of the two possible α-cleavages at the carbonyl function was observed. The major decomposition processes are outlined and compared with the recent results of a study on α,β-unsaturated aliphatic ketones. Mechanistic pathways are suggested for the formation of the major fragment ions.

scholarly journals SIGNIFICANCE OF THE HYDROXYL GROUPS OF STEROIDS IN PROMOTING GROWTH

1954 ◽  
Vol 100 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Charles Huggins ◽  
Elwood V. Jensen
Keyword(s):  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Critical Importance ◽  
Hydrogen Atoms ◽  
Albino Rat ◽  
Ketone Group ◽  
Related Compounds

The presence of a 17ß-hydroxyl group endows the simple androstane molecule with the ability to produce growth of the uterus, vagina, and prostate of the female hypophysectomized albino rat. It appears that hydrogen atoms at position 17 are of critical importance since related compounds with a ketone group at this site are inactive. Monofunctional steroids with a hydroxyl or a ketone group at position 3 likewise are devoid of activity. If a phenolic A-ring is present in monofunctional steroids the 17ß-hydroxyl group is not obligatory for growth. Proliferation of the uterus and vagina were found to follow the administration of 17-desoxyestradiol.

The Mass Spectra of Imidoyl Halides and Bromoiminium Bromides

1973 ◽  
Vol 51 (1) ◽  
pp. 132-138 ◽  
Author(s):  
J. Gal ◽  
B. A. Phillips ◽  
R. Smith
Keyword(s):  
Mass Spectrometer ◽  
Alkyl Group ◽  
Mass Spectra ◽  
Halogen Atom ◽  
Fragmentation Pattern ◽  
Inlet System ◽  
Molecular Ion ◽  
Major Process ◽  
Hydrogen Rearrangement

The mass spectra of imidoyl halides 1–6 and bromoiminium bromides 7–9 have been studied and their fragmentation pattern discussed. Loss of halogen atom from the molecular ion of imidoyl halides to form a N-alkylnitrilium ion is a major process. When the N-alkyl group is larger than methyl the fragmentation of N-alkylnitrilium ions with hydrogen rearrangement to give the [PhC≡NH]+ ion becomes important. Thermolysis of bromoiminium bromides in the inlet system of the mass spectrometer produces imidoyl bromides via dealkylation (or dehydrobromination) and α,α-dibromobenzylamines via addition of bromide to the C=N bond.

Fragmentation of isomeric dideoxy derivatives of 1,6-anhydro-β-D-hexopyranoses under electron impact

1981 ◽  
Vol 46 (10) ◽  
pp. 2390-2403 ◽  
Author(s):  
František Tureček ◽  
Tomáš Trnka ◽  
Miloslav Černý
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Positional Isomers ◽  
Deuterium Labeling ◽  
Stereochemical Assignment ◽  
Electron Impact Mass ◽  
Derivatives Of ◽  
Impact Mass

Electron impact mass spectra of all possible dideoxy derivatives of 1,6-anhydro-β-D-hexopyranoses and their sixteen specifically deuterium-labeled derivatives are reported. The spectra of positional isomers differ considerably making possible the reliable location of the hydroxyl group by mass spectrometry. The configuration of the hydroxyl group at C(2) and C(4) has only a negligible effect on the fragmentation pattern of stereoisomers. However, mass spectra of the C(3)-configurational isomers differ sufficiently to permit a stereochemical assignment. The fragmentation paths were elucidated by means of deuterium labeling and metastable spectra.

Tautomerism of uracil and related compounds: A mass spectrometry study

2017 ◽  
Vol 24 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Diego D Colasurdo ◽  
Matías N Pila ◽  
Dacio A Iglesias ◽  
Sergio L Laurella ◽  
Danila L Ruiz
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Mass Spectra ◽  
Tautomeric Form ◽  
Ion Trap ◽  
Theoretical Calculations ◽  
Ion Trap Mass Spectrometry ◽  
Mass Spectrometry Study ◽  
Related Compounds ◽  
Substituted Uracils

It has been demonstrated that uracil has a preponderant tautomeric form, but it is also known that different tautomers co-exist in this equilibrium. In this work, mass spectrometry is used as a helpful tool to analyse the equilibria, using derivative compounds to forbid the presence of some tautomers and ion trap mass spectrometry to follow relevant fragmentation pathways. Theoretical calculations were performed to confirm tautomers abundance by energy minimization in gas phase. Analysis of mass spectra of uracil, three methyl-substituted uracils, 2-thiouracil and three benzouracils suggest that uracil exists mainly as three tautomers in gas phase: one major structure that corresponds to the classical structure of uracil (pyrimidine-2,4(1H,3H)-dione) bearing two carbonyls and two NH moieties, and two minor enolic forms (4-hydroxypyrimidin-2(1H)-one and 2-hydroxypyrimidin-4(1H)-one). Such tautomeric distribution is supported by theoretical calculations, which show that they are the three most stable tautomers.

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