Mass spectra and structure of imines of 2-aroylbenzamides

Abstract

The electron impact mass spectra and DADI spectra of anils of N-alkyl-2-benzoylbenzamides and 2-alkyl-3-arylamino-3-phenylisoindolinones isomeric to them, as well as certain 2-substituted 3-alkyl(aryl)amino-3-phenylisoindolinones, were studied. The main direction of the decomposition were described. It was established that transition from 2-aroylbenzamides to their imines leads to a substantial stabilization of the cyclic isomeric form. A stabilization of the cyclic form with increasing steric volume of the alkyl substituent at the azomethine nitrogen atom was noted. The presence of a phenyl substituent at the nitrogen atom of the amide group destabilizes the cyclic form. A mechanism of isomerization explaining these phenomena is proposed.