147032-07-3Relevant articles and documents
Studies on Pyrazines. Part 25. Lewis Acid-promoted Deoxidative Thiation of Pyrazine N-Oxides: New Protocol for the Synthesis of 3-Substituted Pyrazinethiols
Sato, Nobuhiro,Kawahara, Kazunori,Morii, Noritsugu
, p. 15 - 20 (2007/10/02)
Reaction of 3-substituted pyrazine 1-oxides eith p-methoxytoluene-α-thiol in the presence of diethylcarbamoyl chloride in refluxing acetonitrile gave the corresponding 3-substituted 2-(methoxybenzylthio)pyrazines.Based on these yields, the ease of substitution is remarkably affected by nucleophilicity of the N-oxide oxygen.Addition of zinc bromide to the reaction mixture increased the yields of thiation products of 3-methyl-, 3-phenyl-, 3-(N-butylcarbamoyl)-, 3-methoxycarbonyl- and the parent pyrazine 1-oxides, but their regioselectivies were rather low.The Lewis acid-mediated reaction of 3-methoxypyrazine 1-oxide gave a different major product, the 2,6-isomer.Conversion of the sulfides to pyrazinethiols was accomplished by mercuriation and successive reduction.This debenzylation was also found to be dependent on the electron density in the pyrazine-ring.
