Dv. Ramana et E. Kantharaj, DUAL ORTHO INTERACTION IN UBSTITUTED-3-(2-METHYLPHENYL)-4(3H)-QUINAZOLINONES AND THEIR THIO ANALOGS UNDER ELECTRON-IMPACT CONDITIONS, Journal of mass spectrometry., 30(2), 1995, pp. 262-268
Competing ortho interactions, involving the C=X and the ortho-methyl s
ubstituent on the 3-phenyl moiety, resulting in the eliminations of (C
H3)-C-. and (OH)-O-./(SH)-S-. from the molecular ions of ubstituted-3-
(2-methylphenyl)-4(3H)-quinazolinones and their thio analogues, were o
bserved An intramolecular aromatic substitution of the heteroatom of C
=X at the ortho-carbon of the 3-phenyl moiety ejecting the methyl grou
p and a hydrogen transfer from the same ortho-methyl substituent to th
e heteroatom of C=X resulting in the expulsion of (.)XH are envisaged
for the dual ortho interaction, Another expected fragmentation process
observed in these compounds is the transfer of the aryl group from th
e 3-position of the heterocycle to the heteroatom of C=X leading to th
e elimination of ArX(.) from the molecular ions, The proposed fragment
ation processes and the ion structures are supported by high-resolutio
n data, B/E and B-2/E linked-scan spectra, collisionally activated dec
omposition B/E spectra and deuterium isotopic labelling.