Naphthylamine is an aromatic amine which can be obtained from nitronaphthalene
(with iron and hydrochloric acid) or naphthol with sodium acetate, ammonium
chloride. There are position isomers; 1-naphthylamine and 2-naphthylamine.
2-Naphthylamine
was used as an Intermediate for wide application target molecules including
dyestuffs, agrochemicals, and antioxidants. But its use is restricted or
prohibited due to cancer suspect. Naphthylamine is the naphthalene homologues of aniline. Naphthylamine is the
starting material in the dye manufacturing and rubber industry. Numerous sulfo- and nitro-group substituted
naphthylamine on the ring system offer important roles to each characteristic
colours directly and in preparing next target colorants. Phenyl group
substituted naphthylamines are naphthalene homologues of phenylenediamines used
as parent compounds in vulcanization accelerators and in antioxidants for rubber
industry. Naphthylamine can be oxidized by chromic acid into naphthoquinone
which is the fundamental ring structure related with vitamin K.
Tetrahydronaphthylamine can be oxidized by potassium permanganate into adipic
acid. Naphthyl structure is found as a ligand in transition-metal catalyts
particularly in the form of bi-naphthyl which is composed of two naphthyl rings
connected at one carbon site on each ring.
Sulfonic acid is
a compound with general formula RSO2OH, where R is an
aliphatic or aromatic hydrocarbon. It is a derivative of sulfuric acid
(HOSO2OH) where an OH has
been replaced by a carbon group or a compound where a hydrogen atom has been
replaced by treatment with sulfuric acid; for example, benzene is converted to
benzenesulfonic acid (water-soluble). Sulfonic acid has a sulfur atom bonded to
a carbon atom of a hydrocarbon and bonded also to three oxygen atoms, one of
which has been attached to a hydrogen atom. Sulfonic acid is acidic due to the
hydrogen atom, stronger than a carboxylic acid. Sulfonic acid is one of the most
important organo sulfur compounds in organic synthesis. Sulfonic acids are used
as catalysts in esterification, alkylation and condensation reactions.
Sulfonates are salts or esters of sulfonic acid. Sulfonic salts are soluble in
water. Sulfonic acid and its salts present in organic dyes provide useful
function of water solubility and or improve the washfastness of dyes due to
their capability of binding more tightly to the fabric.
Peri Acid
and its derivatives are
used directly in making several dyes and
converted
into numerous dye intermediates. The reagent grade of
Phenyl peri acid is used as a fluorescent probe for protein studies.
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