Acid Brown 121

Preparation

4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid?diazo, Coupled with resorcinol, 4-Nitrobenzenamine diazo, and the generation of single accidentally coupled nitrogen compounds, its product again with diazo of 2-Amino-4-nitrophenol coupling.

Properties and Applications

dark yellow light brown. Soluble in water for brown. The strong sulfuric acid for wine, dilute after brown precipitation. In water solution to join strong hydrochloric acid with brown precipitation; Join rare sodium hydroxide solution for red brown.