Diazotization


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diazotization

[dī‚az·ət·ə′zā·shən]
(organic chemistry)
Reaction between a primary aromatic amine and nitrous acid to give a diazo compound. Also known as diazo process.

Diazotization

 

the reaction of preparing diazo compounds by the action of nitrous acid (or its derivatives) on primary amines in the presence of inorganic acids (HCl, H2SO4, or HNO3) at 0°-5°C. The diazotization of aromatic amines to yield diazonium salts is the most common—for example, aniline is diazotized to phenyldiazonium chloride:

In organic synthesis, diazotization is used extensively to make various aromatic compounds through the diazonium salt, as well as to synthesize dyes, particularly azo dyes.

References in periodicals archive ?
Key words: Congo Red dye, Diazotization, Spectroscopic techniques, Water hardness.
Azo-compounds (1-7) were prepared by diazotization of 4-methoxyaniline and 4aminophenazone followed by treating with active aromatic compounds at temperature below 5degC [7].
Nitration, sulfonation, amination, halogenation, reduction, oxidation and diazotization are distinctive chemical process used in the preparation of these dyes.
We have designed and synthesized a series of novel helix-shaped molecules having five and seven conjugated rings via an iterative protocol of coupling reactions followed by diazotization reactions.
The most commonly used nitrite assay is based on the Griess diazotization reaction, which is specific for nitrite and does not detect nitrate.
For example, they have been converted to imidazo[2,1-b]thiazole by reaction with dibenzoylacetylene [15] or with a-haloketones [16,17], to hetarylazoindole dyes via diazotization and coupling with indole compounds [18], to Schiff bases by reactions with aldehydes [19-21], to 2-(2-chloroacetamido)-thiazole which can serve as an electrophile in a variety of nucleophilic substitution reactions: with secondary amines [22,23], thiols [24] and with phenols [25].
Advantage was taken of the fact that a facile ring-forming diazotization reaction was to follow a straight forward novel Ullmann coupling triarylation.
This cassette contains a complete reagent system that translates the enzyme-mediated oxidation of cholesterol and cholesterol esters into a visible and measurable color bar, produced by the horseradish peroxidase-catalyzed reaction of hydrogen peroxide with 3-methyl-2-benzothiazolinone hydrazone followed by diazotization of an immobilized aniline dye.
In this work, three novel vinylsulfone based azo reactive dyes were successfully synthesized by successive condensations, diazotization and coupling reaction steps using reactive acids i.
The presence of the functions aromatic primary amine is essential for conversion to diazonium salt by a diazotization reaction in acid medium allows the electrochemical grafting of the entity that these functions by reduction of diazonium salts as shown by the work of Finch and BACopyrightlanger [39].
Keywords: Butachlor Spectrophotometry Diazotization Coupling Dye Environmental sample.
Summary: Reactive dyes were synthesized from cyanuric chloride and 1-amino-8-hydroxy- naphthalene-3-6-disulphonic acid by condensation diazotization activation and coupling reaction.