Cyclization of the Molecular Ions of N-[2-(Cyclopent-1-en-1-yl)phenyl]arylamides upon Electron Impact

Abstract

Analysis of the electron impact mass spectra, collision-induced dissociation spectra, and high-resolution mass spectrometry data of N-[2-(cyclopent-1-en-1-yl)phenyl]arylamides and isomeric 2-arylspiro[3,1-benzoxazine-4,1'-cyclopentanes] indicated that only a small portion of the molecular ions of the arylamides undergo cyclization to give the corresponding substituted 3,1-benzoxazines prior fragmentation. The donor-acceptor properties of the benzene ring substituents affect the efficiency of cyclization of the molecular ions.