5227-56-5Relevant academic research and scientific papers
A new efficient route for the formation of quinoxaline N-oxides and N,N′-dioxides using HOF·CH3CN
Carmeli, Mira,Rozen, Shlomo
, p. 5761 - 5765 (2007/10/03)
HOF·CH3CN, a very efficient oxygen-transfer agent made readily from fluorine and aqueous acetonitrile, was reacted with various quinoxaline derivatives to give the corresponding mono N-oxides and especially the N,N′-dioxides in very good yields under mild conditions and short reaction times.
An unexpected course of the Meisenheimer reaction : aryl phosphates in the reaction of phosphoryl chloride with 2,3-diphenylquinoxaline-N1-oxide.
Nasielski, J.,Heilporn, S.,Nasielski-Hinkens, R.,Geerts-Evrard, F.
, p. 4329 - 4338 (2007/10/02)
Contrary to what is observed with other ?-deficient heteroaromatic N-oxides, the reaction of 2,3-diphenylquinoxaline-N1-oxide with OPCl3 gives only very poor yields of chlorinated quinoxalines.It is shown that the major product arises from an unprecedented attack by the nucleophilic oxygen atom of the reagent at a carbon atom of the homocycle of the O-phosphorylated N-oxide, leading ultimately to the corresponding mono- (or di-) aryl ester of phosphoric acid.Using a much smaller excess of OPCl3 and dilution of the medium with an inert solvent strongly increase the yield of chlorination products.It is suggested that, after the initial O-phosphorylation, phosphate formation might be the primary step in all the Meisenheimer reactions.
