Odiaminobenzene

O-diaminobenzene, also known as o-phenylenediamine or 1,2-diaminobenzene, is an aromatic diamine in which two amino groups occupy adjacent positions on a benzene ring. Its formula is C6H4(NH2)2. The compound is typically a colorless to pale yellow solid that is soluble in water and alcohols. Like other primary amines, the amino groups can be diazotized under acidic conditions, enabling a range of electrophilic coupling reactions used in dye and pigment synthesis.

Industrial relevance: o-Phenylenediamine is produced and used as a chemical intermediate. It serves as a versatile building block for various products, including azo dyes, pigment intermediates, and heterocyclic compounds such as benzimidazole derivatives. It is also used in certain polymer and polyurethane formulations and as a reagent in organic synthesis.

Safety and handling: It is an irritant and potential sensitizer. Exposure may cause skin and eye irritation and may be harmful if swallowed or inhaled. It should be handled in a fume hood with appropriate personal protective equipment, and waste should be disposed of as hazardous. Nitrosating conditions can generate N-nitroso compounds from aromatic amines, so precautions are taken to limit nitrite exposure and to prevent formation of such species.