Tobias acid (2-amino-1-naphthalenesulfonic acid) is an
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...
with the formula C
10H
6(SO
3H)(NH
2). It is named after the German chemist Georg Tobias. It is one of several
aminonaphthalenesulfonic acid Aminonaphthalenesulfonic acids are compounds with the composition C10H6(NH2)(SO3H), being derived from naphthalene (C10H8) substituted by an amino and sulfonic acid groups. These compounds are colorless solids. They are useful precursors to dyes ...
s, which are derivatives of
naphthalene containing both
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 ...
and
sulfonic acid functional groups. It is a white solid, although commercial samples can appear otherwise.
It is used in the synthesis of
azo dyes
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N=N ...
such as C.I. Acid Yellow 19 and C.I. Pigment Red 49. It is prepared via the
Bucherer reaction The Bucherer reaction in organic chemistry is the reversible conversion of a naphthol to a naphthylamine in the presence of ammonia and sodium bisulfite. The reaction is widely used in the synthesis of dye precursors aminonaphthalenesulfonic ac ...
of
2-hydroxynaphthalene-1-sulfonic acid with ammonia and ammonium sulfite.
[Gerald Booth "Naphthalene Derivatives" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2005, Wiley-VCH, Weinheim. .]
References
External links
2-Amino-1-naphthalenesulfonic acid NIST Standard Reference Data Program
Naphthylamines
Sulfonic acids
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