6-Amino-1-naphthalenesulfonic acid
[CAS# 81-05-0]

Identification

• Classification: Organic raw materials >> Amino compound >> Sulfonic acid amino compound
• Name: 6-Amino-1-naphthalenesulfonic acid
• Synonyms: D Acid; 2-Amino-5-naphthalenesulfonic acid
• Molecular Formula: C₁₀H₉NO₃S
• Molecular Weight: 223.25
• CAS Registry Number: 81-05-0
• EC Number: 201-318-4
• SMILES: C1=CC2=C(C=CC(=C2)N)C(=C1)S(=O)(=O)O

Properties

• Density: 1.5±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.713, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovory and Applicatios

6-Amino-1-naphthalenesulfonic acid is a chemical compound with both industrial and scientific significance, widely used in various fields including the production of dyes, biochemistry, and molecular biology. The compound consists of an amino group (-NH2) attached to the naphthalene ring, which is also sulfonated at the 1-position, making it both a sulfonic acid and an amine derivative.

The discovery of 6-amino-1-naphthalenesulfonic acid dates back to the late 19th century during the development of azo dye chemistry. It emerged as part of the exploration of naphthalene derivatives, which were of great interest due to their potential as starting materials for a wide range of synthetic dyes. The compound was found to be a key intermediate in the synthesis of various azo dyes, particularly those used in textile industries. Its ability to participate in the formation of diazonium salts made it a versatile building block in dye chemistry. Over the years, the compound's properties have been studied extensively, and its role as an important precursor in dye manufacturing has been well established.

In terms of its applications, 6-amino-1-naphthalenesulfonic acid is primarily used as a starting material in the synthesis of azo dyes. These dyes are widely used in the textile, paper, and food industries for their vibrant colors. The amino group on the naphthalene ring reacts with diazonium salts to form azo compounds, which are then used as dyes. The sulfonic acid group enhances the solubility of these dyes in water, making them ideal for use in aqueous applications, particularly in textile dyeing processes.

In addition to its use in the production of dyes, 6-amino-1-naphthalenesulfonic acid is also utilized in biochemical research. It serves as a reagent in the synthesis of various molecular probes and has been incorporated into assays for studying enzyme activity, especially in reactions involving sulfonation. The compound's amino group and sulfonic acid group allow it to interact with various biological molecules, making it useful in the development of probes and other tools for molecular biology.

Another significant application of 6-amino-1-naphthalenesulfonic acid is in the field of fluorescence spectroscopy. When incorporated into certain molecules, it can act as a fluorescent marker. The compound’s ability to absorb light at specific wavelengths and re-emit it at longer wavelengths is harnessed in fluorescence-based detection methods. This application is important in various analytical techniques, including the detection of biomolecules, environmental monitoring, and diagnostics.

6-amino-1-naphthalenesulfonic acid also plays a role in the development of chemical sensors. By modifying its structure, it is possible to create compounds that can detect a variety of analytes, including ions, gases, and other small molecules. These sensors are valuable in environmental monitoring and industrial applications, where precise detection of chemical substances is crucial.

In summary, 6-amino-1-naphthalenesulfonic acid is a compound with a long history of use in dye synthesis and biochemical research. Its ability to form azo dyes, enhance solubility, and serve as a reagent in biochemical assays makes it valuable in multiple industries, including textiles, biotechnology, and environmental monitoring. As a building block in the synthesis of complex molecules, its versatility continues to make it an important substance in both industrial and scientific applications.

References

Kim, Y.D., Lee, J.J., 2023. An investigation on thermal decomposition behavior of water-soluble azo dyes. Fibers and Polymers, 24, 2799�2806.
DOI: 10.1007/s12221-023-00275-9

Thakur, J.K., Paul, S., Dureja, P., et al., 2014. Degradation of sulphonated azo dye Red HE7B by Bacillus sp. and elucidation of degradative pathways. Current Microbiology, 69, 183�191.
DOI: 10.1007/s00284-014-0571-2

Liu, H.-Y., et al., 2007. catena-Poly[[(6-aminonaphthalene-1-sulfonato-[κ]O)silver(I)]-[μ]-2,3,5,6-tetramethylpyrazine-[κ]N:N']. Acta Crystallographica Section E: Structure Reports Online, E63, m3035.
DOI: 10.1107/S1600536807049550