Acid Orange 7
Acid Orange 7, also known as 2-naphthol orange is an azo dye. It is used for dyeing wool. Preparation
It is produced by azo coupling of β-naphthol and diazonium derivative of sulfanilic acid. References

Azo dyes
Benzenesulfonates
Organic sodium salts
2-Naphthols
Acid dyes