Mv. Gorelik et al., INTERACTION OF ANILINE WITH DIAZOTIZING AND NITRATING AGENTS IN CONCENTRATED SULFURIC-ACID, Mendeleev communications, (2), 1995, pp. 64-65
The interaction of aniline with nitrosonium hydrogensulfate then with
nitric acid in concentrated sulfuric acid does not occur through diazo
tisation and subsequent nitration of the benzenediazonium ion, but ins
tead involves nitrosonium ion catalysed nitration of anilinium ion in
the para-position together with uncatalysed nitration in the meta- and
para-positions followed by diazotisation on dilution with water.