Naphthamine yellow NN

Chloramine Yellow FF (Naphthamine Yellow NN) and Thiazole Yellow... 

Naphthamine yellow NN is the most light-fast yellow for cotton and is completely stable to chlorine. Because of these properties, it is widely used, especially in the United States where laundry is always treated with bleaching agents. Naphthamine yellow NN is not as pure a color as chrysophenine and is inferior also with respect to color strength. 

Naphthamine yellow NN, 335 Naphthalene, 1, 53 catalytic oxidation, 171 Naphthalene-1,5-disulfonic add, 219... 

Various types of dyes are prepared from dehydrothiotoluidine. The free base or its sulfonic acid is diazotized and coupled with various naph-tholsulfonic acids such as, for example, e acid (l-naphthol-3,8-disul-fonic acid). The resulting dye is characterized by its high purity of color and can be discharged to a pure white. Such red direct dyes are sold under various names, and are usually referred to as dyes of the erika red type. (Erika Z is the combination from dehydxothioxylidine and e acid. l-Naphthol-3,6-disulfonic acid gives a very similar dye.) In addition to the true azo dyes from dehydrothiotoluidine, two other products are made which are important yellow dyes. One of these dyes is the naphthamine yellow NN (also called chloramine yellow) (Kalle), formed from dehydrothiotoluidinesulfonic acid by oxidation with sodium hypochlorite. The other is thiazole yellow or Clayton yellow, which is made by combining the diazo compound of dehydrothiotoluidinesulfonic acid with a second molecule of the same compound to form a diazoamino compound. 

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