Absorption of toxic quantities by any route causes cyanosis (blue discoloration of lips, nails, skin); nausea, vomiting, and coma may follow. Repeated inhalation of low concentrations may cause pallor, low-grade secondary anemia, fatigability, and loss of appetite. Contact with eyes causes irritation.
The Detection of blood glucose
Methods of determination of the glucose include oxidase method and o-toluidine condensation method and Folin-Wushi method. Among them, o-toluidine condensation method are most commonly used. This method has a high specificity for detecting glucose and is not affected by other substances other than glucose. The theoretical basis is that glucose in hot acetic acid solution can be condensed with o-toluidine to form a blue-green Schiff's base and the color depth is proportional to the glucose content. O-toluidine is added into the serum and glucose standard liquid. Then compare their optical density and calculate the serum glucose content. The normal level of fasting serum glucose is 70~100mg /dl.
Air & Water Reactions
Becomes reddish brown upon exposure to air and light [Hawley]. Slightly soluble in water.
- O-toluidine is toxic, the inhalation of its vapor or absorbtion through the skin or ingestion can cause poisoning. It is one of the known carcinogens.
- O-toluidine is flammable with a fire point of 482℃, and can form explosive mixture with air. The allowable concentration in air in the United States is 2ppm (9mg/m3).
Toluidine has three isomers: o-toluidine, m-toluidine and p-toluidine, while o-toluidine is the situ substitution product and m-toluidine is the shift substitution product.
O-toluidine is an important intermediate for the production of dyes and pigments and can be used to prepare direct red 62, red base RL, red base G, juvenile base GBC, alkaloid, peptone AS-D, acid red 35,158 265, solvent red 124, diazo group of azo dyes and coupling component, pigment yellow 14, yellow 17, Blue 19; raw materials of pesticide like Tricyclazole, insecticide Chlordimeform, chloromethiuron; acetochlor; raw materials of Thiofide; raw material of saccharin; corrosion inhibitor and other raw materials. In organic synthesis, o-toluidine are also used in synthesis of heterocyclic compounds indole and its derivatives.
Fog water, foam, carbon dioxide, sand.
o-Toluidine can be synthesized from toluene. The direct aromatic amination is very effective when done with a parent nitrenium ion, but o-toluidine can also be synthesized in other ways. For example, by the amination of toluene with methylhydroxylamine or hydroxylammonium salts in presence of aluminum trichloride. The reaction using a nitrenium ion is not regionselective and multiple structural isomers will be present in the product. Figure 2 shows a very general synthesis reaction of o-toluidine and the other products (p-toluidine and m-toluidine). To obtain pure o-toluidine, the isomers need to be separated.
1. In the dilute acid medium, o-nitrotoluene heated together with iron powder and water to synthesize o-toluidine.
2. O-nitrotoluene is preheated with hydrogen in the induction heater and hydrogenated in the presence of copper catalyst to prepare o-toluidine.
3.Toluene is aminated by ammonia sodium with the rhodium-carbon catalyst to produce o-toluidine.
4.Aniline is alkylated with methanol under the catalysis of ferric nitrate and germanium dioxide to produce the finished product o-toluidine.
Specific determination of glucose
o-Toluidine can also be used for measuring serum glucose concentration, in the form of acetic acid–o-toluidine. The o-toluidine reaction for the estimation of glucose concentration in the serum gained massive popularity in the 1970s. This method was mostly used by clinical laboratories. Because of the potential health hazard, the laboratories now have a modified method by using alternative compounds.
Light-yellow liquid, becomes reddishbrown
on exposure to air and light. Soluble in alcohol and ether; very
slightly soluble in water. Combustible.
Chemical and Physical Properties
O-toluidine is a clear colorless or light yellow liquid, may become reddish brown on exposure to air and light, and white precipitate at the presence of formaldehyde. It is slightly soluble in water, soluble in dilute acid, alcohol and ether.
relative density: 1.004(20℃);
melting point:-16.3℃ (β),-24.4℃(α);
boiling point: 199.7℃;
Flash point 185°F;
spontaneous ignition point: 482.2℃;
vapor density: 3.69.
Its vapor can form explosive mixture with air. The maximum allowable concentration in air is 5ppm. O-toluidine is flammable when exposed to heat or flame. It will, when heated, emit toxic gases toxic similar to that of aniline. Once it enters human body, it will cause the formation of hemoglobin, resulting in the occurrence of neurological disorders and cyanosis.
It has about the same density as water and is very slightly soluble in water. Vapors are heavier than air. Confirmed carcinogen.
The chemical properties of the toluidines are quite similar to those of aniline and toluidines have properties in common with other aromatic amines. Due to the amino group bonded to the aromatic ring, the toluidines are weakly basic.
TWA 22 mg/m3; STEL 44 mg/m3.
Special Hazards of Combustion Products: Toxic oxides of nitrogen and flammable vapors may form in fire.
Dangerous Goods Code: 84182.UN No.：1708/6270/6.1-02/335.
Domestic commodity number: 61750；
Container in transportation must be marked “Poisonous”.
Suitable protective clothing should be equipped during the peration to prevent skin contact. Wear protective glasses to prevent contact with skin and eyes. Immediately remove permeable clothing, such as wetted or contaminated,. The operating site shall be provided with a safety signal indicator, eyewash and flushing equipment.
If it enters the eyes, immediately rinse with water or eye drops; on the contact with the skin, immediately wash it off with soap and water; if it inhaled, immediately remove the patient from the scene to the fresh air; practice artificial respiration if necessary; if it is swallowed, drink plenty of water and induce vomiting followed by gastric lavage, and immediately send the patient to hospital for treatment. Methylene blue is a specific antidote to it.
In general, methods similar to those for purifying aniline can be used, e.g. distillation from zinc dust, at reduced pressure, under nitrogen. Berliner and May [J Am Chem Soc 49 1007 1927] purified it via the oxalate. Twice-distilled o-toluidine is dissolved in four times its volume of diethyl ether, and the equivalent amount of oxalic acid needed to form the dioxalate is added as its solution in diethyl ether. (If p-toluidine is present, its oxalate precipitates and can be removed by filtration.) Evaporation of the ethereal solution gives crystals of o-toluidine dioxalate [Beilstein 12 III 1494, 12 IV 1817]. These are filtered off, recrystallised five times from water containing a small amount of oxalic acid (to prevent hydrolysis), then treated with dilute aqueous Na2CO3 to liberate the amine which is separated, dried (CaCl2) and distilled under reduced pressure. The benzoyl derivative has m 144o (from EtOH). [Beilstein 12 H 772, 12 I 372, 12 II 429, 12 III 1837, 12 IV 1744.]
A clear colorless or light yellow liquid. May become reddish brown on exposure to air and light. Flash point 185°F. Has about the same density as water and is very slightly soluble in water. Vapors are heavier than air. Confirmed carcinogen.
O-toluidine has a toxicity similar to aniline. The inhalation of its vapor or absorbtion through the skin or ingestion can cause poisoning. Once it enters human body, it will cause the formation of hemoglobin, resulting in the occurrence of neurological disorders, anoxia, headach, acratia, dizziness, drowsiness, cyanosis and hematuresis under microscope. Contact with eyes and skin may cause dermatitis and eye burns. It is one of the known carcinogens.
(Toxicity studies on animals: acute P.O. toxicity on rat LD50: 670 mg/kg, acute P.O. toxicity on mice LD50: 520 mg/kg
Skin irritation on rabbit 10 mg x 24 h, severe. Eye irritation on rabbit 0.75 mg x 24 h, severe.)
Stored in glass bottles or metal barrels to prevent mechanical damage. Place it in a cool, dry, well ventilated place. It is best to use the open or attached warehouse. No fireworks, far away from the fire site. Avoid light. Sealed preservation. Separate it from oxidizer.
Separation of toxic metal ions
The increasing level of heavy metals in the environment is a serious environmental problem. Various methods have been developed to remove these metals from aqueous systems, but these methods have limitations. Because of the limitations, researchers prompted to exploit inorganic materials as ion exchangers. These inorganic ion exchangers are able to obtain specific metal ions/anions or organic molecules. Following research in 2010, there has been a synthesis and analytical application on a new thermally stable composite cation exchange material: poly-o-toluidine stannic molybdate. This material showed a high selectivity for Pb2+ and Hg2+ metal ions.
ChEBI: An aminotoluene in which the amino substituent is ortho to the methyl group.
o-Toluidine neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen may be generated in combination with strong reducing agents, such as hydrides. Emits very toxic oxides of nitrogen when heated to decomposition. Undergoes a hypergolic reaction with red fuming nitric acid [Kit and Evered, 1960, p. 239, 242].
o-Toluidine is used or applied in different circumstances. It is used the most for dye, especially for coloring hair. The other usages of o-toluidine are specific determination of glucose in blood and the most recent one, the separation of toxic metal ions, which is still in the research phase.
o-Toluidine has been used as a dye precursor since the 19th century, when synthetic dye was produced.In the years that followed, the aromatic amine functioned as a precursor of many dyes and pigments for consumer goods. But when the carcinogenicity of o-toluidine for animals was recognized, and that it potentiality could be carcinogenic for humans, the production of o-toluidine and its use in dye manufacturing has been largely banned in the Western world and in many parts of the East. But there are still a few dyes that are based on this compound. The most known compounds are petroleum products and yellow organic pigments. It is also an essential compound in the production of 4-chloro-o-toluidine and 4-amino-2′,3-dimethylazobenzene, which are also dyes.
o-Toluidine (ortho-toluidine) is an organic compound with the chemical formula C7H9N.o-Toluidine is primarily used in the manufacture of dyes. o-Toluidine is highly toxic to humans when absorbed through the skin, inhaled as vapor, or swallowed. Acute (short-term) exposure of humans to o-toluidine affects the blood (i.e., methemoglobinemia), with clinical signs of central nervous system depression. The chronic (long-term) effects in workers exposed to o-toluidine include anemia, anorexia, weight loss, skin lesions, central nervous system depression, cyanosis, and methemoglobinemia. Animal studies indicate that chronic exposure to o-toluidine causes effects on the spleen, liver, urinary bladder, and blood. Occupational exposure to dyestuffs (including o-toluidine) is associated with an increased risk of bladder cancer. 2-Methylaniline hydrochloride (the hydrochloride salt of o-toluidine) was carcinogenic in rats and mice. o-Toluidine has been classified by EPA as a Group B2, probable human carcinogen.
Determination in air: analysis by silica adsorption, propyl alcohol treatment and gas chromatography.
It was used in determination of glucose in biological materials.It was used as precursor in the synthesis of poly(o-toluidine) and copper nanoparticle composite material.
A carcinogenic and toxic aromatic amine contained in hair dye, henna and dyed hair samples.