76641-11-7Relevant academic research and scientific papers
ipso-Attack in the Nitration of Aromatic Amines. Part 2. Isolation of Salts and Other Products resulting from ipso-Attack
Helsby, Paul,Ridd, John H.
, p. 311 - 316 (2007/10/02)
In 70percent nitric acid at 0 deg C, NN,2,4,6-pentamethylaniline undergoes ipso-attack at the 4-position to form the relatively stable ipso-intermediate (2); this ion can be precipitated as the hexafluorophosphate.In more aqueous media, the dimethylamino group is displaced by water to form the hexadienone (4).In aqueous nitric acid at 0 deg C, NN,2,4-tetramethyl-6-nitroaniline undergoes both ipso-attack and addition of water to the ring to form the adduct (8); this ion can also be precipitated as the hexafluorophosphate.The reaction of NN,2,6-tetramethyl-4-methoxyaniline with 52 percent nitric acid at 0 deg C also involves displacement of the dimethylamino group and gives finally 2,6-dimethylbenzoquinone.The initial stages of the reactions of the above amines require the presence of nitrous acid and the reactions are inhibited by hydrazine.
