141305-44-4Relevant articles and documents
A general synthesis of bis(o-azaheteroaryl)methane derivatives from N-oxides of azines and azoles
Szpunar, Magdalena,Loska, Rafa?
supporting information, p. 2133 - 2137 (2015/03/31)
A general method of preparation of derivatives of bis(o-azaheteroaryl)methanes from aromatic N-oxides is reported, the key step of which is a 1,3-dipolar cycloaddition between N-oxides of azines or azoles and in situ generated terminal difluoroalkenes containing an o-azaheteroaryl substituent at the double bond. Selected products were applied for the preparation of two novel unsymmetrical analogues of BODIPY fluorescent dyes, containing both an imidazole and a quinoline or isoquinoline unit.
Palladium-Catalyzed Direct Arylation of Azine and Azole N-Oxides: Reaction Development, Scope and Applications in Synthesis
Campeau, Louis-Charles,Stuart, David R.,Leclerc, Jean-Philippe,Bertrand-Laperle, Megan,Villemure, Elisia,et al.
supporting information; experimental part, p. 3291 - 3306 (2009/07/30)
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New Methods for the Introduction of Substituents into Thiazoles
Begtrup, Mikael,Hansen, Lars Bo L.
, p. 372 - 383 (2007/10/02)
New methods for the regioselective introduction of substituents into thiazoles have been developed using thiazole, 2-phenylthiazole and 4,5-dimethylthiazole as representative thiazoles.Improved halogenation methods, displacement of hydroxy groups in combination with dehalogenation at C-5 yield all eight possible 2-phenyl-4-halo-, 5-halo and 4,5-dihalo-thiazoles in which halogen is chlorine and bromine.Peracid oxidation of the thiazoles gives the corresponding thiazole 3-oxides.These are not activated towards halogenation but are deprotonated with sodium hydride.The anion formed react with electrophiles such as paraformaldehyde, 2,2-dimethylpropanal, 2,2-dimethylpropanoyl chloride, hexachloroethane, tetrabromomethane, and dimethyl disulfide leading to the introduction of carbon substituents, halogen, and methylthio groups.In these reactions, the reactivity of the thiazole ring positions decreases in the order 2 than 5 than 4.Monoselectivity is low when halogen and methylthio groups are introduced since these substituents enhance the acidity of adjacent ring protons. 2-Phenyl-4,5-dihalothiazole 3-oxides lose the 5-halogen when treated with sulfite ion.Trimethyloxonium tetrafluoroborate O-methylates thiazole 3-oxides.Thiazole N-oxides also react with acetyl chloride and phosphorus oxychloride to afford chlorothiazoles in a non-selective manner.Phosphorus trichloride deoxygenates thiazole 3-oxides.
