Ponzio reaction

What is Ponzio reaction?

The Ponzio reaction, which involves the transformation of ketoximes into gem-dinitro compounds through a pseudonitrole intermediate using dinitrogen tetraoxide N2O4, was first reported by Scholl in 1888 and extended by Born in 1896. However, it was Ponzio who initially extended this reaction to aromatic compounds in 1897.

Ponzio reaction - general reaction scheme
Ponzio reaction

X = Me, NO2, etc. (see list of acronyms)

The Ponzio reaction is particularly effective for aromatic oximes, such as p-tolylaldoxime and anisaldoxime, and results in the formation of gem-dinitro compounds, along with some other by-products such as benzaldoxime peroxide, diphenylglyoxime peroxide, and benzaldehyde. Notably, the oximes of a few aliphatic ketones, such as acetone, ethyl methyl ketone, diethyl ketone, methyl propyl ketone, methyl isopropyl ketone, and di-n-propyl ketone, can also be converted into corresponding gem-dinitro compounds.

It has been reported that the oxidation of glyoximes, such as dimethyl, methyl, and phenyl glyoximes, yields glyoxime peroxides as the predominant products, whereas the oxidation of mono-oxime of 1,2-diketone by dinitrogen tetraoxide N2O4 leads to the formation of 1,2-diketone, carboxylic acid, and gem-dinitro compounds from C-C bond cleavage. It should be noted that meta-nitro dinitrophenylmethane, which is produced from meta-nitro benzaldehyde oxime, is a more potent explosive than TNT.