Xylidine

Xylidine can refer to any of the six isomers of xylene amine, or any mixture of them. All isomers are toxic.

The chemical formula of xylidines is C₈H₁₁N, or (CH₃)₂C₆H₃NH₂. They are stable and combustible and react with strong oxidizing agents. They may be light sensitive. The CAS number for the isomer mixture is 1300-73-8. They are typically yellow liquids (except 3,4-xylidine which is solid) that darken when exposed to air and light. They are miscible with ethanol and diethyl ether and slightly soluble in water.

Xylidines are produced as byproducts of fractional distillation of coal tar.

Their risk and safety phrases are R20 R22 R36 R37 R38.

Xylidines are chiefly used in production of pigments and dyestuffs, and also various antioxidants, agrochemicals, pharmaceuticals, and many other organic chemicals.

Xylidines are also used as a component of the Tonka rocket fuel.

2,3-xylidine

2,3-xylidine, also called o-xylidine, 2,3-dimethylaniline, 2,3-xylylamine, or 2,3-dimethylphenylamine, is a liquid with melting point 2.5 °C and boiling point 222 °C, and flash point at 96 °C. Its CAS number is 87-59-2 and its SMILES structure is Nc1cccc(C)c1C. It is used in production of mefenamic acid, dyes, and pesticides.

2,5-Xylidine

2,5-Xylidine is a compound with formula (CH₃)₂C₆H₃NH₂. It is an aromatic amine.

It is an isomer of 2,6-xylidine and 2,4-xylidine.

3,4-Xylidine

3,4-Xylidine (3,4-dimethylaniline) is a organic compound with formula (CH₃)₂C₆H₃NH₂. It is an aromatic amine and a xylidine isomer. It is a crystalline solid.

Preparation and applications

The compound is prepared by two routes: hydrogenation of (2-chloromethyl)-4-nitrotoluene and reaction of the bromoxylene with ammonia. It is a precursor for the production of riboflavin (vitamin B₂).

Safety

Like other xylidines, 3,4-xylidine has modest toxicity with an LD₅₀ of 812 mg/kg when administered orally to rats.

In 2003, more than twenty US Army troops were allegedly exposed to 3,4-xylidine during the occupation of Iraq, leading to a number of health complaints.

References