Nitriles from hydrazonium salts

Quaternary hydrazonium salts (derived from aldehydes) give nitriles when treated with OEt or DBU (p. 488, 1337) as do dimethylhydrazones RCH— NNMe2 when treated with Et2NLi and HMPA. All these are methods of converting aldehyde derivatives to nitriles. For the conversion of aldehydes directly to nitriles, without isolation of intermediates, see 16-21. 

Quaternary hydrazonium salts (derived from aldehydes) give nitriles when treated with OEr391 or DBU (p. 1023) 392... 

Hydrazones stemming from aldehydes are easily converted into nitriles. For example, when treated with alkylating agents hydrazones form hydrazonium salts [232], which upon ehmination give nitriles as the formally oxidized products. Alternatively, hydrazones can be oxidized directly, and for this reaction oxidants such as peracids [233], oxone [234] and dioxirane [235] were found to be effective. Finally, catalytic systems based on combinations of hydrogen peroxide with metal catalysts [236] or selenium compounds [237] have been developed for this process. Other reactions along these lines include oxidations of monohydrazones giving diazo compounds [238] or nitrilimines [239] and conversions of vicinal dihydrazones into alkynes [240]. 

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See also in sourсe #XX -- [ ]

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