5-Naphthol-7-sulfonic acid, 2-amino-6- chromium complexes

A similar argument can be applied to the results of later work by Idelson et al.i9 In this they prepared the chromium complex (133) by interaction of the 1 1 chromium complex of 1-phenyl-3-methyl-4-(2-hydroxy-4-cyanonaphth-l-ylazo)-5-pyrazolone and diethylenetriamine and by reaction of the azo compound with [Cr(CO)3dien]. Identical products were obtained and, since the diethylenetriamine occupies9 a facial position in [Cr(CO)3dien], it was concluded that the complex (133) had a facial configuration. Similarly, the reported77 separation of isomeric 2 1 chromium complexes of 2-amino-6-(2-hydroxy-6-nitro-4-sulfonaphth-l-ylazo)-5-naphthol-7-sulfonic acid is... 

In the stepwise synthesis of the unsymmetrical complex dye 13 [ 70236-60-1] [10], the azo dye made from diazotized l-amino-2-hydroxy-5-nitrobenzene and 1-phenyl-3-methyl-5-pyrazolone and the 1 1 chromium complex obtained from 6-nitro-l-diazo-2-hydroxynaphthalene-4-sulfonic acid and 2-naphthol are heated together at 80 °C for 5 h. The adduct is salted out with NaCl. A black powder is obtained that dyes wool and leather in dark brown shades. The resulting colors are fast, particularly on shrink-resistant wool. 

First, 1 2 metal complexes of (mainly mono-) azo dyes, without sulfonic or carboxylic acid groups, and trivalent metals (see Section 3.11). The metals are preferably chromium and cobalt nickel, manganese, iron, or aluminum are of lesser importance. Diazo components are mainly chloro- and nitroaminophenols or amino-phenol sulfonamides coupling components are (3-naphthol, resorcinol, and 1-phe-nyl-3-methyl-5-pyrazolone. Formation of a complex from an azo dye and a metal salt generally takes place in the presence of organic solvents, such as alcohols, pyridine, or formamide. An example is C.I. Solvent Red 8, 12715 [33270-70-1] (1). 

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