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Mass spectrometric and pyrolytic behavior of some arylsubstituted isoxazolines
Author(s) -
Dallakian P.,
Bei H.,
Schäfer M.,
Budzikiewicz H.
Publication year - 1998
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(199804)33:4<346::aid-jms641>3.0.co;2-d
Subject(s) - chemistry , chemical ionization , pyrolytic carbon , mass spectrometry , hydroxylamine , fast atom bombardment , aryl , fragmentation (computing) , electron ionization , pyrolysis , thermal decomposition , medicinal chemistry , gas chromatography , organic chemistry , chromatography , ionization , ion , alkyl , computer science , operating system
The synthesis and mass spectrometric (MS) and pyrolytic behavior of three 3,5‐aryl‐substituted isoxazolinyl acetophenones, 2‐[4,5‐dihydro‐5‐(4‐methoxyphenyl)‐3‐phenyl‐5‐isoxazolyl]‐1‐phenylethanone (I), 2‐[4,5‐dihydro‐5‐(4‐methoxyphenyl)‐3‐phenyl‐5‐isoxazolyl]‐1‐(4‐methylphenyl)ethanone (II) and 2‐[4,5‐dihydro‐5‐(4‐methoxyphenyl)‐3‐(4‐methylphenyl)‐5‐isoxazolyl]‐1‐phenylethanone (III) are discussed. Compound I and the mixture of the isomeric compounds II and III were prepared by the reaction of 2,4,6‐arylpyrylium salts with hydroxylamine. The substances were investigated using electron ionization, positive chemical ionization with methane and fast atom bombardment. The isomeric compounds II and III were separated by gas chromatography (GC)/mass spectrometry. MS/MS and high‐resolution MS were used to establish the fragmentation mechanisms. The thermal decomposition products obtained by off‐line pyrolysis/GC/MS of I–III were compared with the MS fragments. The results of the investigation will facilitate themin detection and identification of 3,5‐aryl‐substituted isoxazolinyl acetophenones in plant extracts. © 1998 John Wiley & Sons, Ltd.