Nitrosation Nitrosodimethylaniline

Nitrosation, of amides with dinitrogen tetroxide, 47, 46 of N-phenylglycine, 45, 96 p-Nitrosodimethylaniline, reaction with o-nitrobenzylpyridinium bromide, 46, 82... 

Nitrosobenzene, CjHsNO, which is obtained by the oxidation of phenylhydroxylamine, and p>nitrosodimethylaniline, p-(CH3)2NCjH4NO, which is easily prepared by the nitrosation of dimethylaniline, are fairly specific oxidizing agents for the preparation of aromatic aldehydes from benzyl halides or tosylates and of a-dicarbonyl compounds from from a-halo ketones [984, 985]. Also, a methylene group flanked by two carbonyls can be oxidized to a carbonyl group by nitrosodimethylaniline [986]. Pyridine is frequently used to form quaternary pyridinium salts from reactive halides prior to their oxidation to aromatic aldehydes, a-ketoaldehydes, or a-diketones [984] (equations 22 and 23). 

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