An azo coupling is an organic reaction between a diazonium compound and an aniline or a phenol. The reaction product is an azo compound. In this reaction the diazonium salt is an electrophile and the activated arene a nucleophile in an electrophilic aromatic substitution. Azo couplings are important in the production of dyes such as methyl red and pigment red 170.

External links

• Azo coupling of o-tolidine and chicago acid in Organic Syntheses Coll. Vol. 2, p.145; Vol. 16, p.12Online article
• Methyl red in Organic Syntheses Coll. Vol. 1, p.374; Vol. 2, p.47 Online article

organic reactions