3,3'-Dichlorobenzidine

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3,3'-Dichlorobenzidine[1]
3,3'-Dichlorobenzidine.svg
Names
IUPAC name
4-(4-amino-3-chlorophenyl)-2-chloroaniline
Other names
(1,1-Biphenyl)-4,4-Diamine,3,3-dichloro; 3,3-dichloro-4,4-biphenyldiamine
Identifiers
CAS number91-94-1
ChEMBLChEMBL314470 YesY
ChemSpider6803 YesY
Jmol-3D imagesImage
KEGGC19225 YesY
PubChem7070
Properties
C12H10Cl2N2
Molar mass253.13 g/mol
AppearanceGray or purple crystalline solid
Melting point132 to 133 °C (270 to 271 °F; 405 to 406 K)
Boiling point402 °C (756 °F; 675 K)
Hazards
Main hazardsPotential carcinogen[2]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY verify (what isYesY/N?)
Infobox references
 
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3,3'-Dichlorobenzidine[1]
3,3'-Dichlorobenzidine.svg
Names
IUPAC name
4-(4-amino-3-chlorophenyl)-2-chloroaniline
Other names
(1,1-Biphenyl)-4,4-Diamine,3,3-dichloro; 3,3-dichloro-4,4-biphenyldiamine
Identifiers
CAS number91-94-1
ChEMBLChEMBL314470 YesY
ChemSpider6803 YesY
Jmol-3D imagesImage
KEGGC19225 YesY
PubChem7070
Properties
C12H10Cl2N2
Molar mass253.13 g/mol
AppearanceGray or purple crystalline solid
Melting point132 to 133 °C (270 to 271 °F; 405 to 406 K)
Boiling point402 °C (756 °F; 675 K)
Hazards
Main hazardsPotential carcinogen[2]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY verify (what isYesY/N?)
Infobox references

3,3'-Dichlorobenzidine is an organic compound with the formula (C6H4Cl(NH2))2. The pure compound is pale yellow, but commercial samples are often colored. It is barely soluble in water and is often suppled as a wet paste. It is widely used in the production of diarylide dyes and diarylide yellow pigments used in the production of printing inks.[3]

Preparation and reactions[edit]

3,3'-Dichlorobenzidine is prepared in two steps from 2-nitrochlorobenzene. The first step involves reduction with zinc in base to afford 3,3'-dichlorodiphenylhydrazine. This intermediate undergoes the benzidine rearrangement to afford 3,3'-dichlorobenzidine.[4]

Aqueous solutions of 3,3'-dichlorobenzidine degrade in light to monochloro derivative. It undergoes chlorination (for example in water treatment plants) to give the tetrachloro derivative.

The most widely practiced reaction of 3,3'-dichlorobenzidine is its double diazotization to afford [(C6H4Cl(N2))2]2+. This intermediate is then coupled to derivatives of acetoacetylaminobenzene (CH3C(O)CH2C(O)NHAr).[3]

Safety[edit]

3,3'-Dichlorobenzidine is considered a carcinogen.[1] It contains two benzene rings. This compound has been shown to increase the incidence of tumors in animals. [5] Because it is structurally similar to benzidine, a known carcinogen, it is believed that it may share a similar mechanism in causing bladder cancer in humans.[5]

References[edit]

  1. ^ a b Dichlorobenzidine - Compound Summary, PubChem.
  2. ^ NIOSH Pocket Guide to Chemical Hazards 0191
  3. ^ a b K. Hunger. W. Herbst "Pigments, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012. doi:10.1002/14356007.a20_371
  4. ^ Schwenecke, H.; Mayer, D. (2005). "Benzidine and Benzidine Derivatives". Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_539. 
  5. ^ a b "3, 3'-Dichlorobenzidine". U.S. Environmental Protection Agency, Integrated Risk Information System. 7 March 2011. Accessed 3 May 2011.

External links[edit]