2-Tolidine (orthotolidine, o-tolidine; not to be confused with
''o''-toluidine) is an organic compound with the chemical formula (C
6H
4(CH
3)NH
2)
2. Several isomers are known; the 3-tolidine derivative is also important commercially. It is a colorless compound although commercial samples are often colored. It is slightly soluble in water. It forms
salts
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...
with acids, such as the
hydrochloride
In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (e.g. an amine). An alternative name is chlorhydrate, which comes from French. An archaic alternative na ...
, which is commercially available.
2-Tolidine can be produced by a
benzidine rearrangement
Benzidine (trivial name), also called 1,1'-biphenyl-4,4'-diamine (systematic name), is an organic compound with the formula (C6H4NH2)2. It is an aromatic amine. It is a component of a test for cyanide. Related derivatives are used in the produc ...
from a
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
derivative derived from
2-nitrotoluene.
:(CH
3C
6H
4)
2N
2H
2 → (C
6H
3(CH
3)NH
2)
2
Uses
2-Tolidine is a commercial
aromatic amine
In organic chemistry, an aromatic amine is an organic compound consisting of an aromatic ring attached to an amine. It is a broad class of compounds that encompasses anilines, but also many more complex aromatic rings and many amine substituents ...
used mainly for dye production.
[K. Hunger. W. Herbst "Pigments, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2012. ] 2-Tolidine is an intermediate for the production of soluble
azo dye
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N=N ...
s and insoluble pigments used particularly in the textile, leather and paper industries.
:
It has also for the production of certain
elastomer
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic p ...
s.
2-Tolidine was widely used as a reagent or indicator in analytical, clinical and forensic chemistry, such as in the analytical determination of gold, or determination of the
chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...
level in
swimming pool
A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming or other leisure activities. Pools can be built into the ground (in-ground pools) or built ...
water.
Safety
2-Tolidine is toxic and possibly
carcinogen
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...
ic. It is listed as an
IARC Group 2B carcinogen, meaning it is "possibly carcinogenic to humans". Animal studies have shown that animals exposed to tolidine developed tumors in the liver, kidney, and mammary glands.
References
{{Authority control
Biphenyls