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Zincke Reaction
The Zincke reaction is an organic reaction, named after Theodor Zincke, in which a pyridine is transformed into a pyridinium salt by reaction with 2,4-dinitro-chlorobenzene and a primary amine. The Zincke reaction should not be confused with the Zincke-Suhl reaction or the Zincke nitration. Furthermore, the Zincke reaction has nothing to do with the chemical element zinc. Reaction mechanism The first reaction is the formation of the ''N''-2,4-dinitrophenyl-pyridinium salt (2). This salt is typically isolated and purified by recrystallization. Upon heating a primary amine with the ''N''-2,4-dinitrophenyl-pyridinium salt (2), the addition of the amine leads to the opening of the pyridinium ring. A second addition of amine leads to the displacement of 2,4-dinitroaniline (5) and formation of the König salt (6a and 6b). The trans-cis-trans isomer of the König salt (6a) can react by either sigmatropic rearrangement or nucleophilic addition of a zwitterionic intermediate to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodor Zincke
Ernst Carl Theodor Zincke (19 May 1843 – 17 March 1928) was a German chemist and the academic adviser of Otto Hahn. Life Theodor Zincke was born in Uelzen on 19 May 1843. He became a pharmacist and graduated in Göttingen with his Staatsexamen. He began studying chemistry with Friedrich Wöhler and received his Ph.D in 1869. He joined the group of August Kekulé at the University of Bonn, and in 1875 became professor at the University of Marburg where he remained until his retirement in 1913. He developed Zincke reaction, Zincke–Suhl reaction in 1906 (together with R. Suhl) and in 1900 Zincke nitration. Theodor Zincke died on 17 March 1928 in Marburg Marburg ( or ) is a university town in the German federal state (''Bundesland'') of Hesse, capital of the Marburg-Biedenkopf district (''Landkreis''). The town area spreads along the valley of the river Lahn and has a population of approxima .... References * * {{DEFAULTSORT:Zincke, Theodor 1843 births 1928 dea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |