O-Phenylenediamine

O-Phenylenediamine (also known as 1,2-Diaminobenzene) is an organic compound with the formula C6H4(NH2)2. This aromatic amine is an important precursor to many herbicides and dyes. It is isomeric with m-phenylenediamine and p-phenylenediamine, and is commonly referred to as OPD.

Structure and properties

O-Phenylenediamine features a benzene ring with two amino groups (NH2) substituted at the 1 and 2 positions, hence the prefix 'o-' in the name. It is a white solid, although commercial samples can appear dark owing to the presence of impurities.

Synthesis

O-Phenylenediamine is produced industrially by the hydrogenation of nitrobenzene in the presence of a metal catalyst, typically palladium on carbon.

Applications

O-Phenylenediamine is a versatile intermediate, used in the manufacture of a variety of chemical products. It is a key ingredient in the synthesis of agricultural chemicals, rubber chemicals, pharmaceuticals, and dyes.

Safety

O-Phenylenediamine is toxic and can be absorbed through the skin. It is also a suspected carcinogen. Proper safety measures should be taken when handling this chemical.

See also

• Aromatic amine
• Nitrobenzene
• Hydrogenation