Description
o-Anisidine was produced commercially in the United States
from the 1920s until late 1950s. By 2009, worldwide only six
industries manufactured o-anisidine, but none produced
hydrochloride salt. o-Anisidine was available from 44 suppliers,
including 20 US suppliers, and the hydrochloride salt was
available from eight suppliers, including five US suppliers. US
imports of o-anisidine and its hydrochloride salt are reported in
the category ‘o-anisidines, p-anisidines, and p-phenetidine,’ and
US exports are reported in the category ‘anisidines, dianisidines,
phenetidines, and their salts.’ From 1989 to 2008,
imports ranged from a high of over 4.6 million kg in 1996 to
zero in 2007 and 2008, and exports ranged from zero to
262 000 kg. Reports filed under the US Environmental
Protection Agency’s (EPA) Toxic Substances Control Act
Inventory Up Rule indicated that United States production plus
imports of o-anisidine totaled 500 000 lb–1 million lb in 1986,
1990, and 2006; 1 million–10 million lb in 1990 and 1998;
and 10 000–500 000 lb in 2002.
Chemical Properties
Anisidine exists as ortho-, meta-, and paraisomers. They have characteristic amine (fishy) odors.
o-Anisidine (or o-methoxyaniline) is an aromatic amine with a methoxyl group ortho to the amino group of aniline. It is a colorless to yellowish, pink, or reddish liquid.o-Anisidine is soluble in water and mineral oils, and miscible with alcohol, benzene, acetone, and diethylether. o-Anisidine hydrochloride, a salt of o-anisidine, is a grayish crystalline solid or powder at room temperature and is soluble in water (NTP, 2011).
Physical properties
Colorless, yellow to reddish liquid with an amine-like odor. Becomes brown on exposure to air.
Uses
In the preparation of azo dyes; corrosion
inhibitor; chemical intermediate
Uses
It is primarily used as a chemical intermediate in the production
of pigments, dyes, pharmaceuticals, and fragrances.
o-Anisidine hydrochloride is used as a chemical intermediate in
the production of numerous azo and triphenylmethane dyes
and pigments (e.g., C.I. direct red 72, disperse orange 29, direct
yellow 44, direct red 24, and acid red 4); in the production of
pharmaceuticals, including the expectorant guaiacol; as
a corrosion inhibitor for steel; and as an antioxidant for polymercaptan
resins.
Uses
Similar to other aromatic amines, o-anisidine may cause methemglobinemia and cancer in humans. It is used mainly as an intermediate for the production of azo dyes and pigments. Other industrial uses of o-anisidine include synthesis of other dyes and pharmaceuticals, as a corrosion inhibitor for steel, and as an antioxidant for polymercaptan resins (IARC, 1999; HSDB, 2012).
Intermediate for azo dyes and for guaiacol.
Definition
ChEBI: O-anisidine is a substituted aniline that is aniline in which the hydrogen ortho to the amino group has been replaced by a methoxy group. It is used as a chemical intermediate in the synthesis of azo pigments and dyes. It has a role as a reagent and a genotoxin. It is a monomethoxybenzene, a substituted aniline and a primary amino compound.
General Description
Clear, yellowish to reddish or brown liquid with an amine (fishy) odor.
Air & Water Reactions
o-Anisidine darkens on exposure to air. Insoluble in water.
Reactivity Profile
o-Anisidine is sensitive to heat. o-Anisidine is also sensitive to exposure to light. o-Anisidine is incompatible with strong oxidizers. o-Anisidine is also incompatible with acids, acid chlorides, acid anhydrides and chloroformates. o-Anisidine will attack some forms of plastics, rubber and coatings. .
Hazard
Strong irritant. Toxic when absorbed
through the skin. Possible carcinogen.
Health Hazard
o-Anisidine was carcinogenic in
experimental animals.
Fire Hazard
o-Anisidine is combustible.
Safety Profile
Confirmed carcinogen.
Moderately toxic by ingestion. Mutation data
reported. When heated to decomposition it
emits toxic fumes of NOx.
Potential Exposure
Anisidines are used in the manufacture
of azo dyes; pharmaceuticals; textile-processing chemicals
Incompatibilities: Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,bromine, fluorine, etc.); contact may cause fires or explosions.
Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides. Attacks some coatings
and some forms of plastic and rubber.
Carcinogenicity
o-Anisidine is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals.
Environmental Fate
Biological. o-Anisidine should be biodegradable according to OECD guidelines (Brown and
Labouerer (1983).
Chemical/Physical. At influent concentrations (pH 3.0) of 10, 1.0, 0.1, and 0.01 mg/L, the GAC
adsorption capacities were 52, 20, 7.8, and 3.0 mg/g, respectively. At pHs 7 and 9, the GAC
adsorption capacities were 110, 50, 23, and 10 mg/g at influent concentrations of 10, 1.0, 0.1, and
0.01 mg/L, respectively (Dobbs and Cohen, 1980).
Shipping
UN2431 Anisidines, Hazard Class: 6.1; Labels:
6.1-Poisonous materials
Purification Methods
It is separated from the m-and p-isomers by steam distillation. It is also separated from its usual synthetic precursor o-nitroanisole by dissolving it in dilute HCl (pH <2.0) extracting the nitro impurity with Et2O, adjusting the pH to ~8.0 with NaOH, extracting the amine into Et2O or steam distilling. Extract the distillate with Et2O, dry the extract (Na2SO4), filter, evaporate and fractionate the residual oil. Protect the almost colourless oil from light which turns it yellow in color. [Biggs & Robinson J Chem Soc 3881961, Nodzu et al. Yakugaku Zasshi (J Pharm Soc Japan) 71 713, 715 1951, Beilstein 13 IV 806.]
Toxicity evaluation
It is primarily metabolized by cytochrome P450 isozymes, and
it forms two o-anisidine–DNA adducts with DNA. It causes
DNA damage by a metabolite in the presence of metals such
as Cu(II). It can also cause Cu(II)-mediated oxidative DNA
damage.
Waste Disposal
Dissolve in combustible solvent
(alcohols, benzene, etc.) and spray solution into furnace
equipped with afterburner and scrubber, or burn spill
residue on sand and soda ash absorbent in a furnace.
