Other nitration reactions by substitution

An alkyl group is sometimes replaced by a nitro group. This happens particularly when nitrating amines to nitramines. As a classical example, the formation of trinitrophenylmethylnitramine (tetryl) from dimethylaniline can be mentioned (Vol. Ill) 

Some branched alkyl groups, especially the isopropyl group, can readily be replaced by a nitro group, even when they are attached to an aromatic ring. For example, under certain nitration conditions thymol ethers can yield the corresponding trinitro-m-cresol ethers (Giua [198]). Similarly, the nitration of p- cymene may lead to dinitrotoluene (Alfthan [199])  

The nitration reaction that consists in replacing a hydroxyl group by a nitro group is not often used. It is usually applied to tertiary alcohols. For example, tert-butyl alcohol (trimethylcarbinol) reacted with nitric acid to yield tert-nitro-butane in 10% yield in relation to the alcohol weight (Haitinger [4])  

In the aliphatic series the substitution of a carboxyl group by a nitro group can only be accomplished with a small yield. gem-Dinitropropane, for example, is obtained from isobutyric acid (Bredt [200])  

In the aromatic series such a reaction is more often observed. For example, p- dimethylaminobenzoic acid can be nitrated to 2,4-dinitrodimethylaniline (Re-verdin [201])  

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