Azo dye intermediate

Uses. (9-Nitrochlorobenzene is used in the synthesis of azo dye intermediates such as o-chloroaniline (Fast YeUow G Base), i9-nitroani1ine (Fast Orange GR Base), o-anisidine (Fast Red BB Base), o-phenetidine, and (9-aminophenol (see Azo dyes). It also is used in corrosion inhibitors, pigments, and agriculture chemicals. -Nitrochlorobenzene is used principally in the production of intermediates for azo and sulfur dyes. Other uses include pharmaceuticals (qv), photochemicals, mbber chemicals (qv), and insecticides (see Insectcontroltechnology). Typical intermediates manufactured from the para isomer are -lutioaruline (Fast Red GC Base), anisidine, -aminophenol, -nitrophenol, -phenylenediamine, 2-chloro-/)-anisidine (Fast Red R Base), 2,4-dinitrochlorobenzene, and l,2-dichloro-4-nitrobenzene. 

Industrial production is by reduction of the corresponding nitrophenol with iron or hydrazine (167,168). 2-Amino-4,6-dichlorophenol finds important use as an azo-dye intermediate (see Azo dyes). 

Uses Manufacturing azo dyes, intermediates for antioxidants and accelerators for rubber photochemical measurements laboratory reagent dyeing hair and fur. 

Two important azo dye intermediates, Amino J acid and Amino G acid, are also produced by the Bucherer reaction represented as follows ... 

Bucherer reaction. A procedure for preparation of (i-naphthylamineby heating (i-naphthol with a water solution of ammonium sulfite. A sulfite solution is prepared by saturating concentrated ammonia solution with sulfur dioxide and adding an equal volume of concentrated ammonia solution, (i-naphthol is added and the charge is heated in an autoclave provided with a stirrer or a shaking mechanism. (L. F. Fieser). This reaction is also involved in the preparation of several azo dye intermediates, e.g., Tobias acid. 

Derivation Sulfonation of (3-naphthol with 94% sulfuric acid at 95C and recrystallization from a salt. Use Azo-dye intermediate. 

Use Azo dye intermediate. The disodium salt is used as a reagent in detection of nitrogen dioxide in the air. 

Till a few years ago, p-cresidine used to be a very important dye intermediate. However, this was one of the products with an amino (-NH2) group and was in the banned list of 22 azo compounds, by Germany. Though this was not an azo dye intermediate, however, being in the banned category, demand was restricted in Germany and elsewhere. 

EINECS 205-724-2 3-Hydroxynaphthalene-2,7-disulph-onio acid 2-Naphthol-3,6-disulfonic acid 2,7-Naph-thalenedisulfonic acid, 3-hydroxy-. Used as an azo dye intermediate. The disodium salt is used as a reagent to detect nitrogen dioxide in the air. Solid mp dec very soluble in H2O, EtOH, insoluble in Et20. 

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