1-Naphthylamine is an
aromatic
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...
amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen
Hydrogen is the chemical element wi ...
derived from
naphthalene. It can cause bladder cancer (transitional cell carcinoma). It
crystallize
Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposi ...
s in colorless needles which melt at 50 °C. It possesses a disagreeable odor,
sublimes readily, and turns brown on exposure to air. It is the precursor to a variety of dyes.
[.]
Preparation and reactions
It can be prepared by
reducing 1-nitronaphthalene with
iron
Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...
and
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
followed by
steam distillation.
[
]Oxidizing agent
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...
s, such as ferric chloride, give a blue precipitate
In an aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution. The solid formed is called the precipitate. In case of an inorganic chemical reaction leading ...
with solutions of its salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
s. Chromic acid
The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. This kind of chromic acid may be used as a cleaning mixtu ...
converts it into 1-naphthoquinone. Sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...
in boiling amyl alcohol
An amyl alcohol is any of eight alcohols with the formula C5H12O. A mixture of amyl alcohols (also called amyl alcohol) can be obtained from fusel alcohol. Amyl alcohol is used as a solvent and in esterification, by which is produced amyl acetate ...
reduces the unsubstituted ring, giving tetrahydro-1-naphthylamine. This tetrahydro compound yields adipic acid
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annuall ...
when oxidized by potassium permanganate
Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution.
Potassium permanganate is widely used in the c ...
.
At 200 °C in sulfuric acid, it converts to 1-naphthol.
Use in dyes
The sulfonic acid derivatives of 1-naphthylamine are used for the preparation of azo dye. These compounds possess the important property of dyeing unmordanted cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...
.
An important derivative is naphthionic acid
Naphthionic acid is an organic compound with the formula C10H6(SO3H)(NH2). It is one of several aminonaphthalenesulfonic acids, derivatives of naphthalene containing both amine and sulfonic acid functional groups. It is a white solid, although ...
(1-aminonaphthalene-4-sulfonic acid), which is produced by heating 1-naphthylamine and sulfuric acid to 170–180 °C in the presence of crystallized oxalic acid. It forms small needles, very sparingly soluble in water. Upon treatment with the bis(diazonium) derivative of benzidine, 1-aminonaphthalene-4-sulfonic acid gives Congo red
Congo red is an organic compound, the sodium salt of 3,3′-( ,1′-biphenyl4,4′-diyl)bis(4-aminonaphthalene-1-sulfonic acid). It is an azo dye. Congo red is water-soluble, yielding a red colloidal solution; its solubility is greater in organic ...
.
Safety
It is listed as one of the 13 carcinogens covered by the OSHA General Industry Standards.OSHA Standard 1910.1003
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See also
*Used in preparation of aptiganel.
References
{{DEFAULTSORT:Naphthylamine, 1-
Naphthylamines
IARC Group 3 carcinogens
1-Naphthyl compounds