- Synthesis, structural characterization and antioxidative properties of aminopyrazine and imidazolopyrazine derivatives
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The reaction of 2-aminopyrazine 1 with the glyoxal derivatives 2a-c gave the bicyclic imidazolopyrazinones 3a,b and the monocyclic N-substituted aminopyrazines 4b and 5c. Compounds 3 feature unique crystallographic characteristics. Their reactivity towards superoxide anion is about five times the reactivity of Trolox , while the monocyclic pyrazines are inactive.
- Devillers, Ingrid,De Wergifosse, Bertrand,Bruneau, Marie-Pierre,Tinant, Bernard,Declercq, Jean-Paul,Touillaux, Roland,Rees, Jean-Francois,Marchand-Brynaert, Jacqueline
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p. 1481 - 1487
(2007/10/03)
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- Reaction of Arylglyoxals with 2-Amino Heterocycles
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The reaction of some arylglyoxals with a variety of 2-amino heterocycles, including pyridine, diazine, and azole derivatives, has been studied, with or without BF3*Et2O complex as catalyst.On the basis of the isolation of different intermediate carbinolamines and of some crossover cyclization experiments, a reasonable mechanism has been proposed for all these processes.In addition, some structural features of the resulting bicyclic imidazo derivatives having a potential hydroxyl group in position 3 are discussed.
- Alcaide, Benito,Plumet, Joaquin,Sierra, Miguel A.,Vicent, Cristina
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p. 5763 - 5768
(2007/10/02)
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- Imidazopyridazines and an Imidazopyrazine from Pyridazin- and Pyrazin-amines
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The ambiguous condensations of phenylglyoxal with pyridazin-3-amines and pyrazin-2-amine are shown to yield 2-phenylimidazopyridazin-3(5H)-ones and imidazopyrazin-3(7H)-one, respectively.The former products exist as such, at least in the solid state, whereas the latter product exists to a large extent as the corresponding dipolar molecule.The reactions, degradations and n.m.r. spectra of the products are discussed.
- Barlin, Gordon B.,Brown, Desmond J.,Kadunc, Zdenka,Petric, Andrej,Stanovnik, Branko,Tisler, Miha
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p. 1215 - 1220
(2007/10/02)
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