can't read?
7-amino-4-hydroxy-2-naphthalenesulphonic acid is one of the aminohydroxynaphthalenesulphonic that as industrial intermediates for the synthesis of organic, water-soluble dyes are important.
A 1956 (OTTO)7-Amino-4-hydroxy-2-naphthalenesulphonic acid, ≥90% Cas 87-02-5 - used for the preparation of azo dyes. It is important for the production of scarlet-red (monoazo) and red-brown (bisazo) dyes.