Soluble in water, the aqueous solution is magenta color, add concentrated hydrochloric acid is date red; add concentrated sodium hydroxide solution, produce burgundy precipitate. Very soluble in ethanol is lavender. In concentrated sulfuric acid is purple-black, diluted to orange to reddish brown.
2 Moore 3-Amino-4-methoxybenzenesulfonic acid diazo, and N,N’-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea coupling, then ammoniacal copper sulfate solution, to convert it into copper complexes in the complexation of the two methoxy groups are replaced by hydroxyl groups..
![tetrasodium [mu-[[7,7'-(carbonyldiimino)bis[4-hydroxy-3-[(2-hydroxy-5-sulphophenyl)azo]naphthalene-2-sulphonato]](8-)]]dicuprate(4-) Structure](/CAS/GIF/15418-16-3.gif)