Illustrated Glossary of Organic Chemistry

Diazo coupling (azo coupling): The electrophilic aromatic substitution reaction of a diazonium cation with another aromatic ring to form a diazo compound.


Diazo coupling reaction of the phenyl diazonium cation (PhN2+; shown in red) with phenol (PhOH; shown in blue) gives (E)-4-(phenyldiazenyl)phenol, a diazo compound.