Azine dye

A large number of azines were produced in the early decades of industrial dye manufacture. The synthesis was an all-in operation involving a sequence of oxidation reactions. Mauveine (3), for example, was prepared by oxidizing aniline containing o- and /i-toluidines with potassium dichromate in cold dilute sulfuric acid solution. 

Basic azines are predominantly of historical interest. Yellow, red, brown, blue, and black shades can be obtained with these dyes. Today, Nigrosine Spirit Soluble is still used in shoe polish and creme. The sulfonated variety is applied as a leather dye. It is a polymeric dye containing phenazine ring systems, similar to Aniline Black. C.I. SolventBlack 5, 50415 [11099-03-9] (Nigrosine, spirit-soluble) C.I. Solvent Black 7, 50415 1 [8005-02-5] (4) is the free base. 

oxazine, and thiazine dyes were among the earliest of synthetic dyes. The names are derived from the 6-member heterocycHc ring system present in 

The parent lings are always included in phenazine [92-82-0] (4), phenoxazine [135-67-1] (5), oi phenothiazine [92-84-2] (6) ting systems. 

The first of these dyes to be made synthetically was Perkin s mauveine [6373-22 ] which is a substituted phenazine of stmcture (7). 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Mauveine is in a group of azines termed safranine dyes ie, it is a A/-phenyl-phenazonium chloride. Although the stmctures of these dyes are often written to show a positive charge on a particular hetero atom, the charge is in fact distributed through resonance throughout the molecule, thus accounting for their deep color. 

oxazine, and thiazine dyes were among the eadiest of synthetic dyes. The names are derived from the 6-member heterocyclic ring system present in all dyes of these classes 1,4-diazine [290-37-9] (1), 1,4-oxazine [290 17-1] (2), and 1,4-thiazine [290-57-3] (3). 

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Acid amide herbicides Acid anhydrides Acid azine dyes Acid-base catalysis Acid-base chemistry Acid Black [1064-48-8]... 

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