Intermediates for dyes

The aminonaphthols are of minor use but the aminohydroxynaphthalenesulfonic acids are intermediates for dyes, eg, fiber-reactive a2o dyes and plain and meta11i2ed a2o dyes (Table 7). 

Halogenated and 4,5-halogenated derivatives of 1,8-naphthalenedicarboxyHc acid anhydride are useful intermediates for dyes, pigments, and fluorescent whiteners for polymers. 

Nitration of benzene yields nitrobenzene, which is reduced to aniline, an important intermediate for dyes and pharmaceuticals. Benzene is chlorinated to produce chlorobenzene, which finds use in the preparation of pesticides, solvents, and dyes. 

There are at least 3000 different intermediates in current manufacture (over half that number are specifically mentioned in the Colourlndex) and in addition there is a comparatively small number of products manufactured by individual companies for thein own specialties. Only a selection of intermediates can be discussed here, but since 300 of the products probably account for 90% of the quantity of intermediates used, most of the important aspects can be covered. No meaningfiil quantification of wodd tonnage requirements of primaries and intermediates for dyes can be made. 

Pyrroloj2,1 -b) thiazole, formation of, 36 as intermediate for dyes, 36 in synthesis of chain-bridged thiazolocyanines, 58... 

Benzaldehyde is an important intermediate for dyes (see malachite green) many other aldehydes (phenylacetaldehyde, vanillin, piperonal, citral, etc.) are used in perfumery or as flavouring agents. 

Currently, other minor applications include treatment of felled logs for bark beetles, termite control, control of wax moths in beehives, spot treatment of milling machinery, Japanese beetle control in ornamental plants, and as a chemical intermediate for dyes, resins, waxes, and gums (HSDB 1989). 

Uses Intermediate for dyes rubber and agricultural chemicals manufacture of p-nitrophenol. 

Uses Preparation of 3,4-dichloroaniline solvent for a wide variety of organic compounds and for oxides of nonferrous metals solvent carrier in products of toluene diisocyanate intermediate for dyes fumigant insecticide for termites degreasing hides and wool metal polishes degreasing agent for metals, wood, and leather industrial air control disinfectant heat transfer medium. 

Uses Intermediate for dyes and antioxidants inhibits gum formation in gasoline corrosion inhibiter organic synthesis (preparation of p-phenylenediamine). 

Uses Solvent preparation of isophthalic acid, intermediate for dyes insecticides aviation fuel. 

It is used as intermediate for dyes, plastics pharmaceuticals and in anal chem (Refs 2, 3 4) para - colorless crysts, mp 116—17° bp — subl sol in ale, eth, acet, benz w. It is used in pharmaceuticals (Refs 3, 4 5)... 

The major uses of mixed xylene are in aviation gasoline and protective coatings, and as a solvent for alkyd resins, lacquers, enamels and rubber cements. wetrr-Xylene is used as a solvent, as an intermediate for dyes and organic synthesis, especially isophthalic acid and insecticides, and in aviation fuel or// o-xylene is used in manufacture of phthalic anhydride, vitamin and pharmaceutical synthesis, dyes, insecticides, motor fuels para-xylene is used in synthesis of terephthalic acid for polyester resins and fibres, vitamin and pharmaceutical syntheses, and insecticides (Lewis, 1993). 

Naphthalenols, naphthalenediols, and their sulfonated and amino derivatives are important intermediates for dyes, agricultural chemicals, drugs, perfumes, and surfactants. The methods of manufacture include caustic fusion of naphthalene-l-sulfonic acid, hydrolysis of 1-chloro- or... 

Aminonaphthols and Aminonaphtholsiillonic Acids The aminonaphthols are of minor use but the aimnohydroxynaphthalene-sulfonic acids are intermediates for dyes, e.g., fiber-reactive azo dyes and plain and metallized azo dyes (Table 7). A number of A -acyl-, V-alkyl-, and V-arylaminonaphthaleneosulfonic adds arc used as couplers for azo dyes. 

Yidd.—90% theoretical (47 gms.). Crystallises with H O soluble in hot water alkali salts readily soluble important intermediate for dyes. (B., 18, 3172 A., 190, 69.)... 

Naphthoxidine is a very useful intermediate for dyes of this group, and it can be prepared conveniently by treating 1,5-dinitronaphthalene with sulfur in oleum [27], [28], A solution of sulfur in 20 % oleum is added slowly over 35 min to a slurry of 1,6-dinitronaphthalene in concentrated sulfuric acid, maintaining the temperature at 50-55 °C. The dark brown mixture is stirred for a further 10 min at this temperature and then for 30 min at 20 °C. The mixture is then poured onto ice and the suspension filtered. The blue filtrate is made alkaline with sodium hydroxide solution, employing efficient external cooling in order to keep the temperature below 40 °C. The resultant blue precipitate of the sodium salt of naphthoxidine is filtered off and washed with a little water. The solid is extracted with boiling acetic acid, and concentration of the extracts gives lustrous red needles of naphthoxidine. 

Naphthyl acetate can be converted to a-naphtholl49> in a simple manner with recovery of the acetic acid. a-Naphthol is an important intermediate for dyes and insecticides. The new electrosynthesis was successfully carried out on the tonne scale at BASF. 

Nitrochlorobenzene Nitrochlorobenzene isomers are made by nitration of monochlorobenzene. Some of chemicals that can be made from these isomers are phosalone insecticides, antioxidants, rubber chemicals, AZO intermediates for dyes and diamine compounds used in specialty textiles and fibers. An estimated 30,000 tonnes of nitric acid are consumed annually to make nitrochlorobenzenes. 

Intermediate for dyes and pharmaceuticals, solvent, dielectric fluid, vulcanizing agent, and insecticide. Hazards... 

A number of other authors have carried out the nitration of 2-methylnaphtha-lene, mainly as a step in the preparation of a new intermediate for dyes. Lesser, Glasser and Aczel [40] nitrated 2-methylnaphthalene in the presence of acetic acid and Vessely and Kapp [41] used nitric acid alone at low temperature (5-15°C). They obtained a 58% yield of l-nitro-2-methylnaphthalene and an oil which contained 4-Nitro-, 6-nitro- and 8-nitro-2-methylnaphthalenes. Vessely and his co-workers [42, 43] identified qualitatively most of the mononitro derivatives of 2-methylnaphthalene and their reduction products. 

Another application is the manufacture of explosives, hydrazine, amines, amides, nitriles and other organic nitrogen compounds, which serve as intermediates for dyes and pharmaceuticals. 

Nitration can start from toluene or o-mtrotoluene,/Miitrtttoluenc being isolated as an important intermediate for dyes and medicinal products - (Vol. I, p. 277). Nitration is carried out continuously in a series of nitrators through which the toluene or /> nitrotoluene and the nitrating acids How in a countercurrent. In front of the first nitrator is placed an extraction vessel (not shown on the diagram) in wliich the residua) nitric acid and nitro compounds are extracted from the spent acid by toluene. After extraction, the spent acid/toluenc mixture enters the cooling unit. Toluene which now contains some nitrotoluene and acid is separated from the spent acid and enters the nitrator. The spent acid is sent for distillation. 

Application Sulfuryl chloride is used as a chlorination and sulfochlorination agent in the organic chemical industry, in particular for selective chlorination (e.g. for the side chains of aromatic compounds) and in the manufacture of organic intermediates for dyes, pharmaceuticals, pesticides and disinfectants. 

Use Intermediate for dyes and organics, organic inhibitor, bird repellent for seeds. 

Use Chemical intermediate for dyes, flavoring materials, perfumes, and aromatic alcohols solvent for oils, resins, some cellulose ethers, cellulose acetate and nitrate flavoring compounds synthetic perfumes manufacturing of cinnamic acid, benzoic acid pharmaceuticals photographic chemicals. 

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