TY  - JOUR
A1  - Sarodnick, Gerhard
A1  - Linker, Torsten
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Starke, Ines
A1  - Fürstenberg, Sylvia
A1  - Kleinpeter, Erich
T1  - Quinoxalines XV : convenient synthesis and structural study of pyrazolo[1,5-alpha]quinoxalines
N2  - A series of aryloxymethylquinoxaline oximes, hitherto unknown and synthesized from the corresponding aldehydes, afforded in only one step pyrazolo[1,5-;]quinoxalines in the presence of acetic anhydride at high temperatures. A formal [3,5]-sigmatropic rearrangement was proposed as the mechanistic rationale for this unprecedented transformation. Saponification with potassium hydroxide furnished the free phenol derivatives which were studied by NMR spectroscopy and accompanying theoretical DFT calculations, establishing intramolecular hydrogen bonding and the spatial magnetic properties. Additionally, mass spectrometric fragmentation was investigated by B/E-linked scans and collision-induced dissociation experiments. The fragmentation pattern devoted a new gas phase rearrangement process, which proved to be unique and characteristic for pyrazolo[1,5-;]quinoxalines.
Y1  - 2009
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/30167
UR  - http://pubs.acs.org/journal/joceah
SN  - 0022-3263
ER  -