Title: Cassella's Acid F
CAS Registry Number: 494-44-0
CAS Name: 7-Amino-2-naphthalenesulfonic acid
Synonyms: 2-naphthylamine-7-sulfonic acid; b-naphthylamine-d-sulfonic acid
Molecular Formula: C10H9NO3S
Molecular Weight: 223.25
Percent Composition: C 53.80%, H 4.06%, N 6.27%, O 21.50%, S 14.36%
Literature References: Prepn by sulfonation of b-naphthylamine and separation from the 6-amino isomer: Green,
J. Chem. Soc. 55, 33 (1889); from 7-hydroxy-2-naphthalenesulfonic acid and ammonia: Green,
loc. cit.; Wait,
US 1492497 (1924).
Derivative Type: Monohydrate
Properties: Crystals. Sol in 5040 parts cold water, 350 parts boiling water; sol in glacial acetic acid.
Derivative Type: Copper salt
Properties: Orange-yellow crystals. Sparingly sol in water.
Ref: Green, Vakil,
J. Chem. Soc. 113, 35 (1918).
NOTE: Bronner's acid was first described as
6-amino-2-naphthalenesulfonic acid or
2-naphthylamine-6-sulfonic acid. However, this product obtained by sulfonation of b-naphthylamine, was subsequently shown to be a mixture of about equal parts of 6- and 7-amino-2-naphthalenesulfonic acids: Green,
loc. cit.
Use: Both the title compd and its 6-amino isomer are used in the manuf of azo dyes,
e.g., GB 810246 (1959 to Bayer).
