THE MASS SPECTRA OF SOME THIOPHENE 2- AND 3-CARBOXANILIDES

Abstract

Mass spectra of some substituted thiophene-2-carboxanilides and thiophene-3-carboxanilides at 70 eV are reported. Primary main degradation reaction of these compounds occurs by cleavage of the amide bond, followed by CO elimination. The substituent effects on mass spectra are related by the Hammett equation. The plots of log Z/Z₀ for substituted thiophene-3-carboxanilides against [sgrave] (r = 0.972; ρ = 0.486) and [sgrave]⁺ (r = 0.905; ρ = 0.346) are linear. The plot for 3-substituted thiophene-2-carboxanilides against [sgrave] give poor linearity (r = 0.797); ρ = −0.098).