2-Naphthylamine-6-sulfonic Acid (Schaeffer's Acid)
Schaeffer's acid, or 2-naphthylamine-6-sulfonic acid, is an aromatic amine-sulfonic acid used as a diazo component in dye manufacturing. It is explicitly named in HTS 2921.45.25.00 as a derivative of 2-naphthylamine (β-naphthylamine) with sulfonic functionality. This fits Chapter 29's scope for chemically defined amine-function compounds.
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Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If for salts of this specific acid
Organic acid salts classify with the parent acid per Chapter note on salts (C)(1).
If sulfonated without retained amine function
Sulfonated derivatives lacking nitrogen-functions may fall under earlier sulfonic acid headings.
If containing additional organo-sulfur beyond simple sulfonic
Organo-sulfur compounds with complex S-C linkages classify in 2930 per Chapter notes.
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Import Tips & Compliance
• Include HPLC chromatograms verifying single isomer content to distinguish from 2921.45.25 mixtures
• Label with GHS corrosive pictograms and ensure DOT-compliant packaging for sulfonic acids
• Avoid bulk shipments without stabilizers; anticaking agents permitted per Chapter note (f)
Related Products under HTS 2921.45.25.00
o-Naphthionic Acid (1-Amino-2-naphthalenesulfonic Acid)
o-Naphthionic acid is a chemically defined aromatic monoamine derivative with a sulfonic acid group, used primarily as an intermediate in azo dye synthesis. It falls under HTS 2921.45.25.00 as it is specifically listed as 1-amino-2-naphthalenesulfonic acid within the subheading for naphthylamine derivatives and their salts. This compound meets Chapter 29 note (a) for separate chemically defined organic compounds.
5-Amino-2-naphthalenesulfonic Acid (1,5 Cleve's Acid)
5-Amino-2-naphthalenesulfonic acid, also known as Cleve's acid 1,5-isomer, serves as a critical coupler in azo pigment production. It qualifies under HTS 2921.45.25.00 due to its explicit inclusion in mixtures and as a 2-naphthylamine sulfonic derivative. As a separate chemically defined compound, it aligns with Chapter 29(a).
8-Amino-2-naphthalenesulfonic Acid (1,8 Cleve's Acid)
8-Amino-2-naphthalenesulfonic acid (Cleve's acid 1,8-isomer) is a naphthylamine derivative used in direct dye synthesis. Named in HTS 2921.45.25.00 for mixtures containing this compound, it is a chemically defined aromatic amine per Chapter 29 scope. The sulfonic group maintains its amine-function classification.
Tobias Acid (2-Amino-8-naphthalenesulfonic Acid)
Tobias acid is 2-amino-8-naphthalenesulfonic acid, a key intermediate for acid dyes and pigments. Although positionally distinct, its naphthylamine-sulfonic structure aligns with HTS 2921.45.25.00 mixtures provision for similar isomers. It qualifies as an aromatic monoamine derivative under Chapter 29 heading 2921.
Mixed Naphthylamine Sulfonic Acids for Dye Synthesis
This commercial mixture contains 5- and 8-amino-2-naphthalenesulfonic acid isomers as explicitly described in HTS 2921.45.25.00. Used in multi-component dye formulations, it qualifies as an amine-function compound mixture under Chapter 29 note (b) for isomers. The specific naming governs over general provisions.
Sodium Salt of 2-Naphthylamine-6-sulfonic Acid
The sodium salt form of Schaeffer's acid maintains the amine-function classification of the parent acid per Chapter 29 salt note (C)(1). Explicitly covered under HTS 2921.45.25.00 for named naphthylamine sulfonic acid salts. Commonly used in aqueous dye coupling processes.