3059. 3,3′-Dichlorobenzidine

Nomenclature

CAS number: 91-94-1
3,3-Dichloro-(1,1′-biphenyl)-4,4′-diamine; 3,3′-dichloro-4,4′-biphenyldiamine; DCB.
C12H10Cl2N2; mol wt 253.13.
C 56.94%, H 3.98%, Cl 28.01%, N 11.07%.

Description and references

Prepn from o-chloronitrobenzene: Cohn, Ber. 33, 3552 (1900). Review of carcinogenicity studies: IARC Monographs 4, 49-55 (1974); of bioactivation and toxicology: M. M. Iba, Drug Metab. Rev. 21, 377-400 (1990).

Chemical structure

Properties

Needles from alc or benzene, mp 132-133°. Almost insol in water. Readily sol in alc, benzene, glacial acetic acid.

Derivative

Dihydrochloride.

Nomenclature

CAS number: 612-83-9
C12H10Cl2N2.2HCl; mol wt 326.05.
C 44.20%, H 3.71%, Cl 43.49%, N 8.59%.

Properties

Needles. Slightly sol in water, readily in alc.

Caution

Potential symptoms of overexposure are skin sensitization; dermatitis; headache, dizziness; caustic burns; frequent urination, dysuria; hematuria; GI upsets; upper respiratory infection. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 96. 3,3′-Dichlorobenzidine and its dihydrochloride are reasonably anticipated to be human carcinogens: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-87.

Use

Manuf azo dyes and pigments; as an intermediate for the Benzidine Yellow pigments. As curing agent for isocyanate polymers and solid urethane plastics.