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The fragmentation of 5‐ and 3‐substituted thiophene‐2‐carboxamides under electron impact
Author(s) -
Occhipinti Salvatore,
Alberghina Gaetano,
Fisichella Salvatore,
Puglisi Orazio,
Ceraulo Leopoldo
Publication year - 1980
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210151207
Subject(s) - fragmentation (computing) , thiophene , electron ionization , mass spectrum , chemistry , ion , mass spectrometry , polyatomic ion , electron , mass , spectral line , computational chemistry , medicinal chemistry , analytical chemistry (journal) , photochemistry , organic chemistry , physics , chromatography , nuclear physics , ionization , astronomy , computer science , operating system
The 70 eV electron impact mass spectra of twelve 5‐ and 3‐substituted thiophene‐2‐carboxamides are discussed with the aid of exact mass measurements and labelling experiments. All mass spectra exhibit pronounced molecular ions. Some isomeric 5‐ and 3‐substituted title compounds can be differentiated by mass spectrometry. The fragmentation is influenced by a strong ‘ ortho ‐effect’ which activates the NH 3 elimination. In the other cases the most important fragmentation is NH 2 ˙ loss, followed by CO elimination.