10.1002/ardp.19883210506
The research focuses on mass spectrometric investigations of derivatives of phenylacetic acid, specifically examining the loss of ortho-substituents from ionized phenylacetamides. The purpose of this study was to explore the mass spectrometry (MS) behavior of ortho-substituted phenylacetamides, particularly the loss of substituents such as chlorine, bromine, and nitro groups, which result in strong (M-X)+ signals in their 70 and 12 eV mass spectra. The research concluded that the loss of ortho-substituents is position-specific, with additional methoxy substitution facilitating the loss of the ortho-nitro group. The study also discussed the MI- and CAD-spectra of the (M-X')+-ions and proposed that a special ortho-effect might be at play, where the ortho-substituent is replaced by an intramolecular attack of the amide group. Various phenylacetamides, including 2a-h, 3a-g, 4a, b, 5a, b, and others, were synthesized from corresponding phenylacetic acids using SOCl2 and then with aqueous ammonia or dimethylamine. The chemicals used in the process encompassed a range of phenylacetamides with different substituents, such as H, CH3, F, Cl, Br, NO2, and OCH3, among others, to investigate their specific mass spectrometry patterns and fragmentation behaviors.
10.1021/jo00021a014
The research focuses on the modification of the Bischler-Napieralski reaction for the synthesis of 3-aryl-3,4-dihydroisoquinolines. The purpose of this study was to address the inefficiencies of the traditional Bischler-Napieralski reaction in synthesizing 3-arylisoquinolines, which are important intermediates for the synthesis of various isoquinoline alkaloids and potential medicinal agents. The researchers successfully developed a method that avoids the elimination of the amide group as a nitrile via the retro-Ritter reaction by converting it to an N-acyliminium intermediate with oxalyl chloride-FeCl3. This modification resulted in the formation of 3,4-dihydroisoquinolines in moderate to high yields. The chemicals used in the process include (1,2-diphenylethyl)amides, oxalyl chloride, FeCl3, and various amide derivatives such as formamide, acetamide, benzamide, and phenylacetamide. The study concluded that this new method offers a highly effective synthetic route for the asymmetric synthesis of natural products and medicinal agents containing the 3-arylisoquinoline ring system and provides an alternative, mild method for the preparation of simple 3,4-dihydroisoquinolines.
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