Anomalous behavior of aminohydroxynaphthalenesulfonic acids during diazo coupling

  • Freeman H
  • Whaley W
  • Esancy M
 et al. 
  • 4


    Mendeley users who have this article in their library.
  • 12


    Citations of this article.


The effect of pH on the diazo coupling reaction of some commonly used coupling components (J-acid, Gamma acid, H-acid and S-acid) with monosubstituted diazobenzenes has been investigated. The results demonstrate that, contrary to previous reports, selective diazo coupling ortho to an amino group of an aminohydroxynaphthalenesulfonic acid does not occur in weakly acidic (pH 5-6) media. In fact, such media were found to give nearly exclusive diazo coupling ortho or para to the hydroxyl group. The desired amine coupling reactions required a pH of 3.0-3.5 and occurred only with the more reactive diazonium salts. The structures of the dyes obtained were unambiguously determined with the aid of1H-NMR spectroscopy. © 1986.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Harold FreemanNorth Carolina State University

  • Wilson M. Whaley

  • Michelle K. Esancy

  • James F. Esancy

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free