Tobias Acid (2-Naphthylamine-8-sulfonic Acid)
Tobias acid is the sodium salt of 2-naphthylamine-8-sulfonic acid, widely used as a diazo component in manufacturing acid dyes and pigments. Classified under HTS 2922.21.4000 due to its status in additional U.S. note 3 to section VI, restricting imports for dye production. It qualifies as an oxygen-function amino-compound with amino, hydroxy, and sulfonic groups.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If for industrial-scale production use vs. laboratory/research quantities
End-use distinctions may shift aniline derivatives to different statistical suffixes, though primary structure determines heading.
If containing organo-sulfur linkages beyond sulfonic acid
Chapter notes specify organo-sulfur compounds in 2930 exclude sulfonated derivatives primarily classified by oxygen functions.
If imported as a salt of a different heterocyclic nitrogen compound
Other organic compounds with nitrogen functions classify in 2942 if not fitting earlier oxygen-function amino-compound headings.
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Import Tips & Compliance
• Confirm quota eligibility under additional U.S. note 3 and apply for import licenses through the Department of Commerce if required
• Include spectroscopic data and purity certificates to distinguish from similar naphthylamine derivatives during customs examination
• Package with stabilizers only as permitted by chapter note (f) to avoid reclassification as a preparation
Related Products under HTS 2922.21.40.00
Schaeffer's Salt (2-Naphthylamine-6-sulfonic Acid)
Schaeffer's salt is a sodium salt of 2-naphthylamine-6-sulfonic acid, a key aminohydroxynaphthalenesulfonic acid derivative used primarily as an intermediate in azo dye synthesis. It falls under HTS 2922.21.4000 as a product described in additional U.S. note 3 to section VI, which covers specific organic compounds subject to quota restrictions for dye production. The compound features both amino and sulfonic acid oxygen functions on a naphthalene ring.
Bayer's Acid Salt (1-Naphthylamine-4-sulfonic Acid Sodium Salt)
Bayer's acid sodium salt serves as a crucial intermediate for direct and reactive dyes, featuring the aminohydroxynaphthalenesulfonic acid structure. It is specifically listed under HTS 2922.21.4000 per additional U.S. note 3 to section VI for quota-controlled dye chemicals. The compound's classification follows chapter rules prioritizing oxygen-function amino-phenols.
Neville-Winter Acid (1-Naphthylamine-5-sulfonic Acid)
Neville-Winter acid is an aminohydroxynaphthalenesulfonic acid used in acid dye manufacturing, subject to HTS 2922.21.4000 quotas under U.S. note 3 to section VI. Its structure with amino group ortho/para to sulfonic acid enables diazotization for azo coupling. Classification adheres to chapter priority for oxygen-function amino-naphthols.
Laurent's Acid (2-Naphthylamine-3,6-disulfonic Acid)
Laurent's acid, a di-sulfonic derivative of 2-naphthylamine, functions as a dye coupler in textile coloration chemistry. Covered by HTS 2922.21.4000 as specified in additional U.S. note 3 for import quotas. Despite two sulfonic groups, it remains classified here due to primary amino-hydroxy-naphthalene structure.
K-acid (4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid)
K-acid serves as an important coupling component for substantive dyes due to its multiple sulfonic groups enhancing water solubility. HTS 2922.21.4000 applies per U.S. note 3 listing for quota purposes. The compound exemplifies oxygen-function amino-naphthols with salt-forming capability.