摘要:
AbstractThe 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 NH3 elimination. In the other cases the most important fragmentation is NH2˙ loss, followed by CO elimination.