@article{HeydenreichKochSarodnicketal.2005,
  author    = {Heydenreich, Matthias and Koch, Andreas and Sarodnick, Gerhard and Kleinpeter, Erich},
  title     = {Quinoxalines XIV : Synthesis, H-1, C-13, N-15 NMR spectroscopic, and quantum chemical study of 1H-pyrazolo[3,4- b]quinoxalines (flavazoles)},
  issn      = {0040-4020},
  year      = {2005},
  abstract  = {The synthesis of a series of 1H-pyrazolo[3,4-b]quinoxalines (flavazoles) by acylation, alkylation, halogenation, and aminomethylation of the parent compound is reported and their structure is investigated by H-1, C-13 and N-15 NMR spectroscopy. The restricted rotation about the partial C, N double bond of the N-acyl derivatives 7-10 is studied by dynamic NMR spectroscopy and the barriers to rotation are determined. In order to assign unequivocally the 15 N chemical shifts of N-4 and N-9, in case of 3-substituted flavazoles, exemplary the H-1, C-13, and N-15 NMR chemical shifts of 34, 35, and 39 are also theoretically calculated by quantum chemical methods [ab initio at different levels of theory (HF/6-3G* and B3LYP/6-31G*)]. (C) 2005 Elsevier Ltd. All rights reserved},
  language  = {en}
}
@article{HilfertSarodnickKempteretal.1998,
  author    = {Hilfert, Liane and Sarodnick, Gerhard and Kempter, Gerhard and Kleinpeter, Erich},
  title     = {1H, 13C and 15 N NMR study and molecular modelling of 2,3- disubstituted quinoxalines with sterically hinderered aromatic and heteroaromatic substituents},
  year      = {1998},
  language  = {en}
}
@article{SarodnickHeydenreichLinkeretal.2003,
  author    = {Sarodnick, Gerhard and Heydenreich, Matthias and Linker, Torsten and Kleinpeter, Erich},
  title     = {Quinoxalines : Part 12: Synthesis and structural study of 1-(thiazol-2-yl)-1H-pyrazolo[3,4-b]quinoxalines - the dehydrogenative cyclization with hydroxylamine hydrochloride},
  year      = {2003},
  language  = {en}
}
@article{SarodnickHilfertKempteretal.1997,
  author    = {Sarodnick, Gerhard and Hilfert, Liane and Kempter, Gerhard and Kleinpeter, Erich},
  title     = {Reactin of 2-(halogenomethyl)-quinoxalines and quinolines with hydroxybenzoic acids and their esters},
  year      = {1997},
  language  = {en}
}
@article{SarodnickLinker2001,
  author    = {Sarodnick, Gerhard and Linker, Torsten},
  title     = {Quinoxalines X : a new and convenient synthesis of 1H-Pyrazolo[3,4-b] quinoxalines (Flavazoles)},
  year      = {2001},
  language  = {en}
}
@article{SarodnickLinkerHeydenreichetal.2009,
  author    = {Sarodnick, Gerhard and Linker, Torsten and Heydenreich, Matthias and Koch, Andreas and Starke, Ines and F{\"u}rstenberg, Sylvia and Kleinpeter, Erich},
  title     = {Quinoxalines XV : convenient synthesis and structural study of pyrazolo[1,5-alpha]quinoxalines},
  issn      = {0022-3263},
  doi       = {10.1021/Jo802398g},
  year      = {2009},
  abstract  = {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.},
  language  = {en}
}
@article{StarkeSarodnickOvcharenkoetal.2004,
  author    = {Starke, I. and Sarodnick, Gerhard and Ovcharenko, V. V. and Pihlaja, Kalevi and Kleinpeter, Erich},
  title     = {Quinoxalines : Part 13: Synthesis and mass spectrometric study of aryloxymethylquinoxalines and benzo[b]furylquinoxalines},
  issn      = {0040-4020},
  year      = {2004},
  abstract  = {A series of new aryloxymethylquinoxalines, benzo[b]- and naphtho[2,1-b] fury] quinoxalines, possessing potential biological activity, was prepared, characterized by IR and NMR spectroscopy and their electron ionization (EI) mass spectra studied in detail. The aryloxymethylquinoxalines were obtained by reacting halogenomethylquinoxalines with bifunctional O-nucleophiles. The benzo[b]furylquinoxalines and naphtho[2, I -b]furylquinoxalines were prepared via two routes, which differed in the order of the two cyclization steps involved in the syntheses. The composition of the ions obtained by El mass spectrometry were determined by accurate mass measurements and the fragmentation pathways clarified by B/E linked scans and collision induced dissociation. The mass spectrometric behaviour of the compounds studied as to the possible loss of OH' radicals proved to be very characteristic. (C) 2004 Elsevier Ltd. All rights reserved},
  language  = {en}
}