Naphthionic Acid

naphthionic acid

[¦naf·thē¦än·ik ′as·əd]
(organic chemistry)
C10H6(NH2)SO3H White powder or crystals that decompose when heated; used to manufacture dyes.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Naphthionic Acid


l-naphthylamine-4-sulfonic acid; colorless crystals. Poorly soluble in water and alcohol. Naphthionic acid loses its water of crystallization upon heating to 130°C and, at higher temperatures, decomposes without melting to yield SO 2.

Naphthionic acid is prepared from α-naphthylamine sulfate, C10H7NH 2• H2SO4, by rearrangement into an at 180°-200°C. Naphthionic acid is an intermediate in the synthesis of azo dyes (for example, Congo red).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.