16025-16-4Relevant academic research and scientific papers
Identification of 2-chloropyrazine oxidation products and several derivatives by multinuclear magnetic resonance
Cmoch, Piotr
, p. 693 - 698 (2007/10/03)
1H, 13C, 14N and 15N NMR chemical shifts were used to prove the structures of the products of 2-chloropyrazine oxidation. It was shown that oxidation by hydrogen peroxide in acetic acid or m-chloroperbenzoic acid leads to the N4-oxide, whereas potassium persulfate in sulfuric acid gives the N1-oxide as the main product. Additionally, the results of NMR measurements of products from the nucleophilic substitution of the chlorine atom by azide anion, yielding the respective azides, and ethylation reactions of both 2-chloropyrazine N-oxides leading to the N-ethyl salts confirm the structures of both isomeric N-oxides. Protonation studies of the compounds obtained are also reported. The favoured protonation site is found to be the N atom that is not hindered by any substituents, and in some cases probably the oxygen atom of the N-oxide function. Copyright
DIAZOTIZATION OF SOME AMINODIAZINE N-OXIDES
Jovanovic, Misa V.
, p. 2011 - 2018 (2007/10/02)
Diazotization of a number of aminopyrazine and aminopyrimidine N-oxides affords intermediate diazonium compounds which can be converted to the corresponding bromo and chloro analogs in the presence of the appropriate halide ions.In some instances, electrophilic aromatic substitution takes place prior to the diazotization step.Nucleophilic halogenation accompanying deoxygenation occurs with 2-aminopyrimidine N-oxide in the same manner as described for some 3-amino-1,2,4-triazine 2-oxides.
