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CAS number 95-70-5 YesY
ChemSpider 6982 YesY
KEGG C19386 N
ChEBI CHEBI:53619 YesY
Molecular formula C7H10N2
Molar mass 122.17
Appearance off white crystals
Density 1.107 g/cm3
Melting point 64 °C (147 °F; 337 K)
Boiling point 273 °C (523 °F; 546 K)
Flash point no
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

2,5-Diaminotoluene is an organic compound with the formula C6H3(NH2)2CH3. It is one isomer of six with this formula. 2,5-Diaminotoluene is a colorless crystalline solid that is commonly used in hair coloring.[1]

Formation and use[edit]

2,5-Diaminotoluene is prepared through electrolytic reduction of 2,5-dinitrotoluene.[2] Other methods include the reductive cleavage of 4-amino-2,3'-dimethylazobenzene as well as the condensation of 2-amino-1-methylbenzene and toluene-4-sulphonyl chloride to produce 4-toluenesulphono-2-toluidide which is then coupled with diazotized aminobenzenesulphonic acid and reduced.[2]

2,5-Diaminotoluene is a substitute for phenylenediamine (1,4-diaminobenzene) in commercial hair dyes. It is preferred because of its lower toxicity. However, many home hair dyes still use phenylenediamine. In these applications, these diamines function as a primary intermediate, which means that it is first oxidized with hydrogen peroxide and then combined with a coupler to form the hair dye.[1] 2,5-Diaminotoluene is commonly used to produce black, drab and warm browns, and shades of blonde and gray hair dyes.[2]

2,5-Diaminotoluene is also known to be used in the production of dyes for textiles, furs, leathers, biological stains and indicators, wood stains, and pigments. Two examples of dyes produced by 2,5-diaminotoluene are Cl Basic Red 2 and Cl Acid Brown 103.[2]


  1. ^ a b T. Clausen "Hair Preparations" in Ullmann’s Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a12_571.pub2
  2. ^ a b c d C. Burnett, W. Bergfeld, D. Velsito, C. Klaassen, J. Marks, Jr, R. Shank, T. Slaga, P. Snyder, and F. Andersen "Final Amended Report of the Safety Assessment of Toluene-2,5-Diamine, Toluene-2,5-Diamine Sulfate, and Toluene-3,4-Diamine as Used in Cosmetics" in International Journal of Toxicology, 2010, vol 29, pages 61S-83S