Tolidine

2-Tolidine^[1]
Names
	Preferred IUPAC name 3,3′-Dimethyl-[1,1′-biphenyl]-4,4′-diamine
	Other names o-Tolidine; Orthotolidine; Diaminoditolyl; Diaminotolyl; Bianisidine; Tolidine blue; 3,3'-Dimethylbenzidine; 4,4'-Bi-o-toluidine
Identifiers
CAS Number	119-93-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:34320 ;
ChEMBL	ChEMBL85109;
ChemSpider	8106 ;
ECHA InfoCard	100.003.962
EC Number	204-358-0;
KEGG	C14443 ;
PubChem CID	8413;
UNII	63HLO2IV6K ;
CompTox Dashboard (EPA)	DTXSID5024059 ;
	InChI InChI=1S/C14H16N2/c1-9-7-11(3-5-13(9)15)12-4-6-14(16)10(2)8-12/h3-8H,15-16H2,1-2H3 Key: NUIURNJTPRWVAP-UHFFFAOYSA-N ; InChI=1/C14H16N2/c1-9-7-11(3-5-13(9)15)12-4-6-14(16)10(2)8-12/h3-8H,15-16H2,1-2H3 Key: NUIURNJTPRWVAP-UHFFFAOYAK;
	SMILES CC1=C(C=CC(=C1)C2=CC(=C(C=C2)N)C)N;
Properties
Chemical formula	C14H16N2
Molar mass	212.296 g·mol−1
Appearance	White to reddish crystals or powder
Density	1.23 g/cm3
Melting point	129 °C (264 °F; 402 K)
Boiling point	300.5 °C (572.9 °F; 573.6 K)
Solubility in water	1.3 g/L
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	potential carcinogen
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H350, H411
Precautionary statements	P201, P202, P264, P270, P273, P281, P301+P312, P308+P313, P330, P391, P405, P501
Flash point	244 °C (471 °F; 517 K)
	NIOSH (US health exposure limits):
PEL (Permissible)	Handle with care
REL (Recommended)	Ca C 0.02 mg/m3 [60-minute] [skin]
IDLH (Immediate danger)	Ca [N.D.]
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

2-Tolidine (orthotolidine, o-tolidine; not to be confused with o-toluidine) is an organic compound with the chemical formula (C₆H₄(CH₃)NH₂)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 with acids, such as the hydrochloride, which is commercially available.

2-Tolidine can be produced by many benzidine rearrangement from a hydrazine derivative derived from 2-nitrotoluene.^[2]

(CH₃C₆H₄)₂N₂H₂ → (C₆H₃(CH₃)NH₂)₂

Uses

2-Tolidine aromatic amine used mainly for dye production.^[3] 2-Tolidine is an intermediate for the production of soluble azo dyes and insoluble pigments used particularly in the textile, leather and paper industries.

Pigment Yellow 16, a derivative of o-tolidine

It has also for the production of certain elastomers.

Orthotolidine in chlorine test kit

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 level in swimming pool water.

Safety

2-Tolidine is toxic and possibly carcinogenic. 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.^[4]

References

^ Record of ortho-Tolidin in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 6.6.2008.
^ Noller, Carl R.: Textbook of Organic Chemistry, Springer Verlag, 1960
^ K. Hunger. W. Herbst "Pigments, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012. doi:10.1002/14356007.a20_371
^ "CDC - NIOSH Pocket Guide to Chemical Hazards - o-Tolidine". www.cdc.gov.

[BGIA_GESTIS-1] Record of ortho-Tolidin in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 6.6.2008.

[2] Noller, Carl R.: Textbook of Organic Chemistry, Springer Verlag, 1960

[Ullmann1-3] K. Hunger. W. Herbst "Pigments, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012. doi:10.1002/14356007.a20_371

[4] "CDC - NIOSH Pocket Guide to Chemical Hazards - o-Tolidine". www.cdc.gov.

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