Premium
Über primäre Disazofarbstoffe mit Aminonaphtol‐sulfonsäuren
Author(s) -
Schneider L.
Publication year - 1968
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19680510106
Subject(s) - chemistry , naphthalene , sulfonic acid , yield (engineering) , amino acid , organic chemistry , polymer chemistry , biochemistry , materials science , metallurgy
Abstract Disazo dyes from 6‐amino‐1‐hydroxy‐naphthalene‐3‐sulfonic acid (J acid) were synthesized by coupling ortho ‐hydroxy monoazo dyes with different diazonium compounds in acid medium (dyes No 3 – 14 . A second coupling to the ortho position of the amino group was also possible with the copper complexes of o , o ' ‐dihydroxy monoazo dyes from 8‐amino‐1‐hydroxynaphthalene‐3,6‐disulfonic acid (H acid) dyes No 19 – 22 ). This is a reversal of the well known rule that the formation of disazo dyes with aminonaphthol‐sulfonic acids is only practicable when an acid coupling is followed by an alkaline one. 5‐Amino‐1‐hydroxy‐naphthalene‐3‐sulfonic acid (M acid), which is said to form no disazo dyes, could be coupled twice with several diazonium compounds to yield disazo dyes (dyes No 24 , 26 , 27 , 29 ).