General Description
Green crystals or white crystalline solid. Melting point 215-217°F. Highly toxic.
Reactivity Profile
O-TOLUIDINE HYDROCHLORIDE(636-21-5) acts as a weak acid. Incompatible with oxidizing agents and with alkalis .
Air & Water Reactions
Insoluble in water.
Fire Hazard
Flash point data for this chemical are not available; however, O-TOLUIDINE HYDROCHLORIDE is probably combustible.
Chemical Properties
white crystalline powder
Uses
o-Toluidine and o-toluidine hydrochloride are used primarily as intermediates in the manufacture of more than 90 dyes and pigments (NCI 1979, IARC 1982, 2000). They are used in acid-fast dyestuffs, azo pigments and dyes, triarylmethane dyes, sulfur dyes, and indigo compounds and as a photographic dye. o-Toluidine is also used as an intermediate for synthetic rubber and rubber vulcanizing chemicals, pharmaceuticals, and pesticides and as a curing agent in epoxy resin systems. Other minor uses of o-toluidine and its hydrochloride salt are as an intermediate in organic synthesis and as an ingredient in a clinical laboratory reagent for glucose and hemoglobin analyses.
Uses
o-Toluidine Chloride is a carcinogenic and toxic aromatic amine contained in hair dye, henna and dyed hair samples. Prilocaine USP Related Compound A
Synthesis
The general procedure for the synthesis of o-biphenylamine hydrochloride from o-nitrotoluene was as follows: the catalyst precursor in the form of 0.04 M CuSO4 and 0.004 M CoCl2 solution (3.0 ml, 3.0 mol/mol CuSO4, 0.3 mol/ml CoCl2) was added to magnetically stirred 25 ml methanol solution of o-nitrotoluene (4 mmol). The reaction was initiated by the addition of an initial portion of 210 mg (5.6 mmol) of NaBH4, and a change in the color of the reaction solution to black (in situ generated catalyst) accompanied by the escape of violent gases was observed. Subsequently, NaBH4 (7 × 35 mg, 7 × 0.9 mmol) was added in portions at 3 min intervals. The reaction was carried out at room temperature and atmospheric pressure, and due to the exothermic nature of the reaction, the temperature of the reaction mixture was usually raised to 30-40 °C, and additional cooling was usually not required for small-scale reactions. For large scale reactions (10 mmol), a reflux condenser needs to be connected. After 25 minutes of reaction, the reaction was quenched by adding 30 ml of water and extracted with 3 x 40 ml of CH2Cl2. The organic layers were combined and dried with MgSO4. After removal of the desiccant, an ether solution (10 ml) of 6 M HCl was added to form a more stable hydrochloride, followed by removal of excess HCl, CH2Cl2, and Et2O under reduced pressure (10 mmHg).The amine products were analyzed by GC-MS, 1H-NMR, and 13C-NMR. The NMR data of the compounds are listed in Table 2.
Carcinogenicity
o-Toluidine and o-toluidine hydrochloride are reasonably anticipatedto be human carcinogens based on sufficient evidence of carcinogenicity from studies in experimental animals.
References
[1] RSC Advances, 2015, vol. 5, # 57, p. 45760 - 45766
[2] Journal of Organic Chemistry, 1982, vol. 47, # 18, p. 3577 - 3581
[3] Organic Preparations and Procedures International, 2014, vol. 46, # 2, p. 176 - 182
