SynCED: Benzidine

Record Information

Version

1.0

Creation Date

2009-03-06 18:57:56 UTC

Update Date

2026-08-18 16:28:09 UTC

Accession Number

CHEM000023

Identification

Common Name

Benzidine

Class

Small Molecule

Description

Benzidine is the organic compound with the formula (C6H4NH2)2. it is an aromatic amine. It is prepared in a two step process from nitrobenzene. First, the nitrobenzene is converted to 1,2-diphenylhydrazine, usually using iron powder as the reducing agent. Treatment of this hydrazine with mineral acids induces a rearrangement reaction to 4,4'-benzidine. Smaller amounts of other isomers are also formed. The benzidine rearrangement, which proceeds intramolecularly, is a classic mechanistic puzzle in organic chemistry. This aromatic amine is a component of a test for cyanide and also in the production of dyes. Benzidine has been linked to bladder and pancreatic cancer. Since August 2010 benzidine dyes are included in the EPA's List of Chemicals of Concern.

Contaminant Sources

Clean Air Act Chemicals
HPV EPA Chemicals
IARC Carcinogens Group 1
My Exposome Chemicals
STOFF IDENT Compounds
T3DB toxins
ToxCast & Tox21 Chemicals

Contaminant Type

Amine
Aromatic Hydrocarbon
Industrial/Workplace Toxin
Metabolite
Organic Compound
Pollutant
Synthetic Compound

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
(1,1'-Biphenyl)-4,4'-diamine	ChEBI
4,4'-Bianiline	ChEBI
4,4'-Biphenyldiamine	ChEBI
4,4'-Biphenylenediamine	ChEBI
4,4'-Diamino-1,1'-biphenyl	ChEBI
4,4'-Diaminobiphenyl	ChEBI
4,4'-Diaminodiphenyl	ChEBI
4,4'-Diphenylenediamine	ChEBI
C.I. azoic diazo component 112	ChEBI
p,P'-bianiline	ChEBI
p,P'-diaminodiphenyl	ChEBI
p-Diaminodiphenyl	ChEBI
4'-Amino[1,1'-biphenyl]-4-ylamine (acd/name 4.0)	HMDB
4, 4'-Biphenylenediamine	HMDB
Biphenyl -4,4'-ylenediamine	HMDB
Fast corinth base b	HMDB
p,P'-diaminobiphenyl	HMDB
p,P'-dianiline	HMDB
p,p-Bianiline	HMDB
Rcra waste number u021	HMDB
[1,1'-Biphenyl]-4,4'-diamine	HMDB
[1,1'-Biphenyl]-4,4'-diamine (acd/name 4.0)	HMDB
{[1,} 1'-biphenyl]-4,4'-diamine	HMDB
Benzidine hydrochloride	HMDB
Benzidine acetate	HMDB
Benzidine monosulfate	HMDB
Benzidine dihydrochloride	HMDB

Chemical Formula

C₁₂H₁₂N₂

Average Molecular Mass

184.237 g/mol

Monoisotopic Mass

184.100 g/mol

CAS Registry Number

92-87-5

IUPAC Name

4-(4-aminophenyl)aniline

Traditional Name

benzidine

SMILES

NC1=CC=C(C=C1)C1=CC=C(N)C=C1

InChI Identifier

InChI=1S/C12H12N2/c13-11-5-1-9(2-6-11)10-3-7-12(14)8-4-10/h1-8H,13-14H2

InChI Key

HFACYLZERDEVSX-UHFFFAOYSA-N

Chemical Taxonomy

Description

Belongs to the class of organic compounds known as benzidines. These are organic compounds containing the benzidine skeleton, made up of a biphenyl ring system substituted at the 4- and 4'-positions with a unsubstituted amine group.

Kingdom

Organic compounds

Super Class

Benzenoids

Class

Benzene and substituted derivatives

Sub Class

Biphenyls and derivatives

Direct Parent

Benzidines

Alternative Parents

Substituents

Benzidine
Aniline or substituted anilines
Organic nitrogen compound
Organopnictogen compound
Hydrocarbon derivative
Primary amine
Organonitrogen compound
Amine
Aromatic homomonocyclic compound

Molecular Framework

Aromatic homomonocyclic compounds

External Descriptors

biphenyls (CHEBI:80495 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Cytoplasm
Extracellular

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Not Available

Biological Roles

Not Available

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	120°C
Boiling Point	Not Available
Solubility	0.322 mg/mL at 25°C

Predicted Properties

Property	Value	Source
Water Solubility	0.4 g/L	ALOGPS
logP	1.59	ALOGPS
logP	1.96	ChemAxon
logS	-2.7	ALOGPS
pKa (Strongest Basic)	4.73	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	2	ChemAxon
Hydrogen Donor Count	2	ChemAxon
Polar Surface Area	52.04 Å²	ChemAxon
Rotatable Bond Count	1	ChemAxon
Refractivity	60.6 m³·mol⁻¹	ChemAxon
Polarizability	21.05 Å³	ChemAxon
Number of Rings	2	ChemAxon
Bioavailability	Yes	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Toxicity Profile

Route of Exposure

Oral (6) ; inhalation (6) ; dermal (6)

Mechanism of Toxicity

N-acetylated benzidine metabolites are believed to form adducts with nucleic acids. Carcinogenesis is initiated when they are activated by peroxidation by prostaglandin H synthetase, oxidation by cytochrome P-450, or O-esterification by O-acetyltransferase or N,O-acetyltransferase. Benzidine has also been shown to bind to RNA and hemoglobin. (6, 1)

Metabolism

Benzidine is absorpted following inhalation, oral, and dermal routes of exposure. Metabolism involves multiple and complex enzymatic pathways, including cytochrome P-450 and flavin monooxygenase systems, peroxidation by prostaglandin H synthase, and oxidation by lipoxygenases. The main reactions involved are N-acetylation, N-oxidation, and N-glucuronidation. Benzidine and its metabolites are excreted in the urine and faeces. (6)

Toxicity Values

LD50: 309 mg/kg (Oral, Rat) (8) LD50: 110 mg/kg (Intraperitoneal, Mouse) (8)

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

1, carcinogenic to humans. (7)

Uses/Sources

Benzidine was used to produce dyes for cloth, paper, and leather. (6)

Minimum Risk Level

Not Available

Health Effects

Benzidine is a known human carcinogen, most often associated with cancer of the urinary bladder. If benzidine comes in contact with skin it may cause a skin allergy. Liver, kidney, immune, and neurological effects have also been observed in animals exposed to benzidine. (6)

Symptoms

Not Available

Treatment

Not Available

Concentrations

Not Available

External Links

DrugBank ID

Not Available

HMDB ID

HMDB0041835

FooDB ID