Mass spectrometric study of 2-keto(thio)tetrahydropyrimidine derivatives

The fragmentation pathways of 2-keto(thio)-6-methyl-5-carbethoxy(acetyl)-4-aryl-1,2,3,4-tetrahydropyrimidines were established using high resolution mass spectra and DADI spectra. An unusual rearrangement was observed, which involves cyclization of the aryl substituent in the 4 position with the oxygen of an ester group and elimination of a C2H5 radical. © 1989 Plenum Publishing Corporation

Mass spectrometric study of 2-keto(thio)tetrahydropyrimidine derivatives

The fragmentation pathways of 2-keto(thio)-6-methyl-5-carbethoxy(acetyl)-4-aryl-1,2,3,4-tetrahydropyrimidines were established using high resolution mass spectra and DADI spectra. An unusual rearrangement was observed, which involves cyclization of the aryl substituent in the 4 position with the oxygen of an ester group and elimination of a C2H5 radical. © 1989 Plenum Publishing Corporation

Mass-spectral investigation of pyrrolo[3,2-c]piperidines

The dissociative ionization of derivatives of pyrrolo[3,2-c]piperidines and their deutero analogs was studied. The successive elimination of the substituents in the piperidine ring, which leads to its aromatization, and cleavage of this ring via a retrodiene fragmentation mechanism are the principal pathways of fragmentation of these substances. The principles found make it possible to determine the position and character of the substituents in the piperidine ring of derivatives of pyrrolo[3,2-c]piperidines. © 1988 Plenum Publishing Corporation

Mass spectra and three-dimensional structures of γ-N-aryl(alkyl)aminopiperidines

The fragmentation of the investigated compounds proceeds with both retention and cleavage of the piperidine ring and makes it possible to distinguish the spatial orientation of the methyl group in the C(5) position of the ring in the analysis of the geometrical isomers of this series. © 1989 Plenum Publishing Corporation

Mass-spectral investigation of pyrrolo[3,2-c]piperidines

The dissociative ionization of derivatives of pyrrolo[3,2-c]piperidines and their deutero analogs was studied. The successive elimination of the substituents in the piperidine ring, which leads to its aromatization, and cleavage of this ring via a retrodiene fragmentation mechanism are the principal pathways of fragmentation of these substances. The principles found make it possible to determine the position and character of the substituents in the piperidine ring of derivatives of pyrrolo[3,2-c]piperidines. © 1988 Plenum Publishing Corporation

Mass spectra and three-dimensional structures of γ-N-aryl(alkyl)aminopiperidines

The fragmentation of the investigated compounds proceeds with both retention and cleavage of the piperidine ring and makes it possible to distinguish the spatial orientation of the methyl group in the C(5) position of the ring in the analysis of the geometrical isomers of this series. © 1989 Plenum Publishing Corporation