Mass Spectral Studies on Some Naturally Occurring Phloroglucinol Derivatives. Part I. The Mass Spectra of Filicinic Acid and its Acetyl, Propionyl, and Butyryl Derivatives.

Some 3-amino-4-aryl-5-aryl(or alkyl)imino-4,5-dihydro-1,2,4-thiadiazol, previously prepared and assigned structures on chemical evidence, are now confirmed in structure by a detailed study of their spectra. While i.r, and n.m.r, spectral data confirm the nature of the ring present in these compounds, mass spectra confirm the assignment of substituents on the ring. Mass spectra of these compounds exhibit specific fragmentation patterns and consequently are useful in structure elucidation of substituted 4,5-dihydro-1,2,4-thiadiazoles.

Download Full-text

Synthesis of phenethanolamine derivatives with potential β-adrenergic antagonistic activity

Australian Journal of Chemistry ◽

10.1071/ch9751023 ◽

1975 ◽

Vol 28 (5) ◽

pp. 1023 ◽

Cited By ~ 4

Author(s):

SJ Pasaribu ◽

LR Williams

Keyword(s):

Magnetic Resonance ◽

Ring Opening ◽

Proton Magnetic Resonance ◽

Mass Spectra ◽

Antagonistic Activity ◽

Spectral Studies ◽

Aryl Ring ◽

Mass Spectral

The mass spectra of bromonitroacetophenones, intermediates in the synthesis of phenethanolamine derivatives containing a nitro and bromo group in the aryl ring, have been studied. The acetophenones were converted into the corresponding α,β-epoxystyrenes, which were then treated with various amines, and proton magnetic resonance and mass spectral studies were used to confirm the direction of ring opening and purity of the products.

Download Full-text

Mass spectral studies of aromatic aza analogues of juvabione

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862879 ◽

1986 ◽

Vol 51 (12) ◽

pp. 2879-2883

Author(s):

R. K. Mahajan ◽

Neelam Gupta ◽

Satinder K. Uppal

Keyword(s):

Mass Spectra ◽

Spectral Studies ◽

Fragmentation Pattern ◽

Mass Spectral ◽

Secondary Amides

Mass spectra of title compounds I-VI have been studied with a view to comparing the fragmentation pattern of secondary amides in different structural environments.

Download Full-text

Mass spectral studies of some desaurins and related 3,5-bismethylene-1,2,4-trithiolanes

Canadian Journal of Chemistry ◽

10.1139/v68-059 ◽

1968 ◽

Vol 46 (3) ◽

pp. 365-375 ◽

Cited By ~ 10

Author(s):

Peter Yates ◽

Thomas R. Lynch ◽

L. S. Weiler

Keyword(s):

Carbonyl Group ◽

Mass Spectra ◽

Molecular Ions ◽

Spectral Studies ◽

Mass Measurements ◽

Metastable Peak ◽

Fragmentation Pathways ◽

Mass Spectral ◽

Accurate Mass Measurements ◽

Doubly Charged

The mass spectra of three desaurins and four related 3,5-bismethylene-1,2,4-trithiolanes have been interpreted with the aid of metastable peak assignments and accurate mass measurements. Strong molecular ion peaks are observed in the case of the aryl desaurins but not in that of their trithiolane counterparts. A variety of fragmentation pathways are postulated for the molecular ions, including cleavage on either side of a carbonyl group and elimination of a molecule of acylthioketene. In the case of the desaurins the latter process results in the formation of acylthioketene molecular ions, which could be distinguished from the doubly charged desaurin molecular ions. In the case of two of the trithiolanes, it is proposed that the ions resulting from loss of acylthioketene from the molecular ions undergo a novel type of McLafferty rearrangement and loss of carbon suboxysulfide to give aryl mercaptan molecular ions.

Download Full-text

Mass spectral studies of lanthanide chelates. II. Lanthanide chelates of three fluorinated β-diketones

Australian Journal of Chemistry ◽

10.1071/ch9761845 ◽

1976 ◽

Vol 29 (8) ◽

pp. 1845 ◽

Cited By ~ 6

Author(s):

SE Livingstone ◽

WA Zimmermann

Keyword(s):

Mass Spectrometer ◽

Mass Spectra ◽

Nitrate Solution ◽

Alcoholic Solution ◽

Spectral Studies ◽

Mass Spectral ◽

Lanthanide Nitrate ◽

Aqueous Alcoholic Solution ◽

Lanthanide Chelates ◽

Chemical Behaviour

The lanthanide chelates MetL3,nH2O (Met = Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, or Yb; L = PhCO= CHCOCF3, p-MeC6H4CO=CHCOCF3, p-MeOC6H4CO=CHCOCF3; n = 2, 3 or 1) have been isolated. The conditions were found to be critical, involving the slow addition of an ammoniacal aqueous alcoholic solution of the β-diketone to an excess of the lanthanide nitrate solution while the pH was maintained within the range 6.0-6.5. The mass spectra of most of the chelates were obtained and were essentially similar and fluorine migration to the metal was found to occur. Although a peak for the ion M-L (M = MetL3+) is present in the spectra, peaks for M-2L and M-3L are absent; however, peaks were obtained for the ions M-2L+ F and M-3L+2F (Met111F2). A peak for the ion M- L+ F (Met11F) was obtained when Met = Sm, Eu and Yb. The valency change from 3 to 2 occurring in the mass spectrometer in the case of samarium, europium and ytterbium is in accordance with their chemical behaviour in solution.

Download Full-text