Peroxymaleic acid compounds

The standard methods of oxidation of pyridines and other heteroaromatic nitrogen compounds make use of peroxy acids or hydrogen peroxide in carboxylic acid solution. Peracetic acid, peroxymono-phthalic acid and MCPBA can all convert simple pyridines to the N-oxides. For example, the pyridine (45) was oxidized at nitrogen by MCPBA without attack on the vinyl group. Peroxymaleic acid has... 

Pyrazinethiones (123) with alkyl halides in the presence of base produce pyrazinylthio compounds (124), which are easily oxidized with peroxymaleic acid to the sulfoxides (125). Cyanomethyl sulfoxide (125 = CN) is alkylated on the methylene carbon between the sulfoxide and cyano... 

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