Mass spectrometry of thio analogues of pyrimidine bases: 2‐and 4‐(E)‐stilbenyloxyalkylthiouracils

Electron impact induced mass spectral study of 2- and 4-ethoxycarbonylalkylthio-5-bromo-6-methyluracils

“…[1][2][3] The differences in mass fragmentation pathways of 2-and 4-alkylthiouracils, 4-6 2-and 4-alkoxycarbonylalkylthiouracils, 7,8 2-and 4-benzylthiouracils, 9 2and 4-(E)-stilbenyloxyalkylthioura-cils, 10 as well as 3-oxothiazolo-[3,2-a]-and- [3,2-c]pyrimidin-5-ones, 11 have been studied previously in our laboratory. [1][2][3] The differences in mass fragmentation pathways of 2-and 4-alkylthiouracils, 4-6 2-and 4-alkoxycarbonylalkylthiouracils, 7,8 2-and 4-benzylthiouracils, 9 2and 4-(E)-stilbenyloxyalkylthioura-cils, 10 as well as 3-oxothiazolo-[3,2-a]-and- [3,2-c]pyrimidin-5-ones, 11 have been studied previously in our laboratory.…”

Mass spectrometry of N‐substituted amino acids and their derivatives: Correlation of the abundances of the M+. and selected fragment ions of metamers

“…The N-substituted 8-phenyl-8-alanines (17,19) may be distinguished from their metameric methyl esters of N-phenylglycines (16,18) on the basis of the highest values of pl and pz .…”

“…The values of p,-pr calculated from the EI mass spectra recorded at 75 eV (15 eV)P of N-(E)stilbenyloxyalkylcarbonyl-substituted a-alanine (3) and fbphenyl-Palanines (6, 9) and their metameric methyl esters (1, 4, 7) and hydrazides (2, 5, 8) and of N-(E)-stilbenyloxyalkylcarbonylsubstituted tryptophan (12, 15) and their metameric methyl esters (10, 13) and hydrazides(11,14) and of N-(E)-stilbenyloxyalkylcarbonyl-substituted /I-phenyl-/I-alanines(17,19) and their metameric methyl esters(16,18) …”

Carbon‐13 chemical shift assignment of (E)‐stilbenyloxyalkylthiouracils

“…10 We now report the I3C NMR spectra of 2-and 4-(E)stilbenyloxyalkylthio-substituted derivatives of uracil (1-3, 7-9) and 6-methyluracil (46, 1&12). 13C NMR data for uracil," 6methyluracil," 2-thiouraci1," 6-methyI-2thiouracil" and (E)-stilben-4-o11' were taken from the literature.…”