Benzidine

	Email		Print
	Bookmark		Link

Benzidine

Benzidine, the trivial name for 4,4'-diaminobiphenyl

Biphenyl

Biphenyl is an organic compound that forms colorless crystals. It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula 2....
, is the organic compound

Organic compound

An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered Inorganic compound....
with the formula

Chemical formula

A chemical formula is a way of expressing information about the atoms that constitute a particular chemical compound, and how the relationship between those atoms changes in chemical reactions....
(C₆H₄NH₂)₂. This aromatic amine

Amine

Amines are organic compounds and functional groups that contain a base nitrogen atom with a lone pair. Amines are derivative s of ammonia, wherein one or more hydrogen atoms are replaced by organic substituents such as alkyl and aryl groups....
is a component of a test for cyanide

Cyanide

A cyanide is any chemical compound that contains the nitrile , which consists of a carbon atom chemical bond to a nitrogen atom. Inorganic cyanides are hydrogen cyanide salts in which cyanide is generally the anion CN-....
and also in the production

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic_chemistry molecules can often contain a higher level of complexity compared to purely Inorganic_chemistry compounds, so the synthesis of organic compounds has developed into one of the most im...
of dyes. Benzidine has been linked to bladder

Bladder cancer

Bladder cancer refers to any of several types of malignant growths of the urinary bladder. It is a disease in which abnormal cells multiply without control in the bladder....
and pancreatic cancer

Pancreatic cancer

Pancreatic cancer is a cancer of the pancreas. Each year in the United States, about 37,680 individuals are diagnosed with this condition and 34,290 die from the disease each year....
.

idine is prepared in a two step process from nitrobenzene

Nitrobenzene

Nitrobenzene, also known as nitrobenzol or oil of mirbane, is an organic compound with the chemical formula Carbon6Hydrogen5NitrogenOxygen2....
. First, the nitrobenzene is converted to 1,2-diphenylhydrazine, usually using iron powder as the reducing agent.

Discussion

Ask a question about 'Benzidine'

Start a new discussion about 'Benzidine'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Benzidine, the trivial name for 4,4'-diaminobiphenyl

Biphenyl

Biphenyl is an organic compound that forms colorless crystals. It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula 2....
, is the organic compound

Organic compound

Chemical formula

Amine

Cyanide

Organic synthesis

Bladder cancer

Pancreatic cancer

Pancreatic cancer is a cancer of the pancreas. Each year in the United States, about 37,680 individuals are diagnosed with this condition and 34,290 die from the disease each year....
.

Synthesis and properties

Benzidine is prepared in a two step process from nitrobenzene

Nitrobenzene

Rearrangement reaction

A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule ....
to 4,4'-benzidine. Smaller amounts of other isomers are also formed. The “benzidine rearrangement”, which proceeds intramolecularly, is a classic mechanistic

Reaction mechanism

In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs .Although only the net chemical change is directly observation for most chemical reactions, experiments can often be designed that suggest the possible sequence of steps in a reaction mechanism....
puzzle in organic chemistry

Organic chemistry

Organic chemistry is a discipline within chemistry which involves the science study of the structure, properties, composition, chemical reaction, and preparation of chemical compounds that contain carbon....
. The conversion is described as a sigmatropic reaction

Sigmatropic reaction

A Sigmatropic reaction in organic chemistry is a pericyclic reaction wherein the net result is one sigma bond changed to another sigma bond. In this type of rearrangement reaction, a substituent moves from one part of a pi-bonded system to another part in an intramolecular reaction with simultaneous rearrangement of the pi system....
:

C₆H₅NH₂⁺NH₂⁺C₆H₅ ? H₃N⁺C₆H₄-C₆H₅NH₃⁺

In terms of its physical properties, 4,4'-benzidine is poorly soluble in cold water but can be recrystallized from hot water, where it crystallises as the monohydrate. It is dibasic, the diprotonated species has pK_a's of 9.3 x 10^-10 and 5.6 x 10^-11. Its solutions react with oxidizing agents to give deeply coloured quinone-related derivatives.

Applications

As with some other aromatic amine

Aromatic amine

An aromatic amine is an amine with an aromatic substituent - that is -nitrogenhydrogen2, -nitrogenhydrogen- or nitrogen group attached to an aromatic hydrocarbon, whose structure usually contains one or more benzene rings....
s such as 2-aminonaphthalene

Naphthalene

Naphthalene, also known as naphthalin, naphthaline, tar camphor, white tar, albocarbon, or antimite and not to be confused with naphtha, is a crystalline, Aromaticity, white, solid hydrocarbon with formula Carbon10hydrogen8 and the structure of two fused benzene rings....
, benzidine has been significantly withdrawn from use in most industries because it is so carcinogenic. In the past, benzidine was used to test for blood

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's Cell s ? such as nutrients and oxygen ? and transports waste products away from those same cells....
. An enzyme

Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
in blood causes the oxidation of benzidine to a distinctively blue

Blue

Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440?490 Nanometre....
-coloured derivative. The test for cyanide

Cyanide

Phenolphthalein

Phenolphthalein is a chemical compound with the chemical formula carbon20hydrogen14oxygen4 . Often used in titrations, it turns colorless in acidic solutions and pink in base solutions....
/hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is a very pale blue liquid which appears colorless in a dilute solution, slightly more viscous than water. It is a weak acid....
and luminol

Luminol

Luminol is a versatile chemical that exhibits chemiluminescence, with a striking blue glow, when mixed with an appropriate oxidizing agent. It is a white to slightly yellow crystalline solid that is soluble in water and most polar organic solvents....
.

Related 4,4’-benzidines

A variety of derivatives of 4,4’-benzidine are commercially produced on the scale of one to a few thousand kilograms per year, mainly as precursors to dyes and pigments. These derivatives include, in order of scale, the following: 3,3'-dichlorobenzidine (CAS# 91-94-1, m.p. 132 – 133 °C), o-tolidine (2,2'-dimethyl-4,4’-benzidine, CAS# 119-93-7, m.p. 130 °C), and o-dianisidine (2,2'-dimethoxy-4,4’-benzidine, CAS# 119-90-4, m.p. 133 °C). 3,3',4,4'-Tetraaminodiphenyl (CAS# 91-95-2, m.p. 178 °C) is a precursor to polybenzimidazole fiber

Polybenzimidazole fiber

Polybenzimidazole or PBI fiber is a synthetic fiber with an extremely high melting point that also does not readily ignite, because of its exceptional thermal and chemical stability....
, a high-strength, flame-resistant material.