Reactions involving displacement of nitrogen
Diazonium group being a very good leaving group, is substituted
by other groups such as Cl
–, Br
–
, I
–
, CN
–
 and OH
– which displace
nitrogen from the aromatic ring The nitrogen  formed escapes from
the reaction mixture as a gas 1 Replacement by halide or cyanide ion: The Cl
–, Br
– and CN
–
nucleophiles can easily be introduced in the benzene ring in the
presence of Cu(I) ion