Mass-spectrometric study of 4-azaphenanthrene derivatives

The mass spectra of 15 compounds of the 4-azaphenanthrene series and their deutero analogs with bulky R substituents (R=-C≡CPh, -CH=CHPh, CHBr-CHBrPh,-CH=CHC6H4OCH3-p, -COOH, -COOC2H5, and -CONHNH2) in the ortho position relative to the nitrogen atom were studied. An intense [M-H]+ ion peak, the appearance of which is evidently due to a process involving cyclization of the carbon atom of the side chain with the nitrogen atom, is formed in the fragmentation of the styryl derivatives. The fragmentation of the compounds with a methyl group in the ortho position relative to the styryl grouping is accompanied by the formation of an intense [M-Ph]+ ion peak. An "ortho effect" of the carboxyl and carbethoxy groups adjacent to the methyl substituent is observed in the mass spectra of the investigated compounds. The data obtained make it possible to establish the structures of bulky substituents in the ortho position relative to the ring nitrogen atom and the position of the methyl group in the pyridine ring of monomethylated azaphenahthrenes. © 1979 Plenum Publishing Corporation

Study of the rearrangement of N-methyl-substituted pyridinium ylides to indolizines by field desorption mass spectrometry

[No abstract available

Mass-spectrometric study of 4-azaphenanthrene derivatives

The mass spectra of 15 compounds of the 4-azaphenanthrene series and their deutero analogs with bulky R substituents (R=-C≡CPh, -CH=CHPh, CHBr-CHBrPh,-CH=CHC6H4OCH3-p, -COOH, -COOC2H5, and -CONHNH2) in the ortho position relative to the nitrogen atom were studied. An intense [M-H]+ ion peak, the appearance of which is evidently due to a process involving cyclization of the carbon atom of the side chain with the nitrogen atom, is formed in the fragmentation of the styryl derivatives. The fragmentation of the compounds with a methyl group in the ortho position relative to the styryl grouping is accompanied by the formation of an intense [M-Ph]+ ion peak. An "ortho effect" of the carboxyl and carbethoxy groups adjacent to the methyl substituent is observed in the mass spectra of the investigated compounds. The data obtained make it possible to establish the structures of bulky substituents in the ortho position relative to the ring nitrogen atom and the position of the methyl group in the pyridine ring of monomethylated azaphenahthrenes. © 1979 Plenum Publishing Corporation

Study of the rearrangement of N-methyl-substituted pyridinium ylides to indolizines by field desorption mass spectrometry

[No abstract available

Mass spectrometric study of methyl-substituted 4-azaphenanthrenes and their nitration products

The mass spectral behavior of five derivatives of the 4-azaphenanthrene series - 1,3-dimethyl-(I), 2,3-dimethyl-(II), 1,2,3,-trimethyl-(III), 1,2,3-trimethyl-8-nitro-(IV), and 1,3-dimethyl-6,7-dinitro-4-azaphenanthrene (V) - was studied. The stabilities of the molecular ions with respect to gragmentation (WM) are higher by a factor of two or more for the methyl-substituted I-III than for nitro derivatives IV and V. The intensity of the [M-H]+ ion peak in the mass spectra of I-V does not depend on the number of methyl groups but only on their positions: the presence of a CH3 group in the 2 position leads to an [M-H]+ ion that is 1.5 times more intense than when there is a methyl group in the 1 position. The molecular ions of I-V do not eliminate HCN molecules; this constitutes evidence for the absence of randomization of their methyl groups. The presence of a CH3 substituent in the 1 or 2 position does not affect the intensity of the [M-CH3]+ ion peaks, while the simultaneous presence of CH3 groups attached to the C1 and C2 atoms increases the intensity of the [M-CH3]+ fragment peak by a factor of two. In the mass spectra of nitro derivatives IV and V, [M-O]+, [M-OH]+, [M-NO]+, and [M-NO2]+ fragments are observed in the first step of the fragmentation of the M+ ion, whereas the [M-CO]+ ion peak characteristic for the dissociative ionization of 1-nitronaphthalene is also observed for 8-nitro-substituted IV. © 1978 Plenum Publishing Corporation

Mass spectrometric study of methyl-substituted 4-azaphenanthrenes and their nitration products

The mass spectral behavior of five derivatives of the 4-azaphenanthrene series - 1,3-dimethyl-(I), 2,3-dimethyl-(II), 1,2,3,-trimethyl-(III), 1,2,3-trimethyl-8-nitro-(IV), and 1,3-dimethyl-6,7-dinitro-4-azaphenanthrene (V) - was studied. The stabilities of the molecular ions with respect to gragmentation (WM) are higher by a factor of two or more for the methyl-substituted I-III than for nitro derivatives IV and V. The intensity of the [M-H]+ ion peak in the mass spectra of I-V does not depend on the number of methyl groups but only on their positions: the presence of a CH3 group in the 2 position leads to an [M-H]+ ion that is 1.5 times more intense than when there is a methyl group in the 1 position. The molecular ions of I-V do not eliminate HCN molecules; this constitutes evidence for the absence of randomization of their methyl groups. The presence of a CH3 substituent in the 1 or 2 position does not affect the intensity of the [M-CH3]+ ion peaks, while the simultaneous presence of CH3 groups attached to the C1 and C2 atoms increases the intensity of the [M-CH3]+ fragment peak by a factor of two. In the mass spectra of nitro derivatives IV and V, [M-O]+, [M-OH]+, [M-NO]+, and [M-NO2]+ fragments are observed in the first step of the fragmentation of the M+ ion, whereas the [M-CO]+ ion peak characteristic for the dissociative ionization of 1-nitronaphthalene is also observed for 8-nitro-substituted IV. © 1978 Plenum Publishing Corporation

Study of the dissociation of imidazoline derivatives by means of a field mass spectrometer

[No abstract available

Study of the dissociation of imidazoline derivatives by means of a field mass spectrometer

[No abstract available