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The Thermal Benzoxazinone‐Benzoxazole Conversion, a Reexecution of a Mass Spectrometric Decay by Thermolysis
Author(s) -
Reichen Werner
Publication year - 1977
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19770600121
Subject(s) - benzoxazole , chemistry , thermal decomposition , aryne , nitrile , carbon monoxide , mass spectrum , photochemistry , decomposition , base (topology) , combinatorial chemistry , medicinal chemistry , organic chemistry , catalysis , ion , mathematical analysis , mathematics
The base peak in the mass spectrum of several 1,4,2‐benzoxazinone derivatives 1a–f ( cf. Scheme 1 and the Table) suggests a clean carbon monoxide elimination leading to benzoxazole radical cations 2a–f . This benzoxazinone‐benzoxazole conversion can be reproduced quantitatively by flash vacuum thermolysis. The isomeric 2,4,1‐benzoxazinone 4 ( cf. Scheme 2 ) eliminates carbon dioxide – the resulting biradical species 5 does not recombine to benzazete 10 but fragments into nitrile and benzyne (7).