Some Manufacturing and Products Improvements

Since many dyes contain aromatic amines one of the most important reactions carried out in the synthesis of dye intermediates is aromatic nitration, involving use of stoichiometric amounts of nitric and sulfuric acid as discussed previously. Many cleaner nitration processes have been proposed, but here discussion will be limited to the use of lanthanide 

Much research has been carried out into direct amination of aromatic substrates, typified by the direct conversion of benzene to aniline using ammonia and a catalyst. Although there have been many patented routes conversions, are normally low, making them uneconomic. Modem catalysts based on rhodium and iridium, together with nickel oxide (which becomes reduced), have proved more active,and such is the research activity in this area that it is only a matter of time before such processes become widely used. 

Reactive dyes are so called because they react with the surface of the 

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