1893. Cassella's Acid F

Nomenclature

CAS number: 494-44-0
7-Amino-2-naphthalenesulfonic acid; 2-naphthylamine-7-sulfonic acid; β-naphthylamine-δ-sulfonic acid.
C10H9NO3S; mol wt 223.25.
C 53.80%, H 4.06%, N 6.27%, O 21.50%, S 14.36%.

Description and references

Prepn by sulfonation of β-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).

Chemical structure

Derivative

Monohydrate.

Properties

Crystals. Sol in 5040 parts cold water, 350 parts boiling water; sol in glacial acetic acid.

Derivative

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 β-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).