N-Hydroxysuccinimide (NHS)
N-Hydroxysuccinimide is an activated ester/imide used in peptide synthesis and bioconjugation chemistry. The imide ring structure qualifies it for HTS 2925.19.91.00 as 'other' imide derivatives despite hydroxy substitution.
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Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If considered cyclic ester of polyhydric alcohol excluded by note 6
Chapter note 6 excludes specific cyclic structures from 2932-2934.
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Import Tips & Compliance
• Biotech end-use requires FDA DMF or equivalent; research use exempt
• Moisture sensitive; specify <0.5% water content on CoA
• Common with EDC coupling agent; declare separately to avoid set classification
Related Products under HTS 2925.19.91.00
Phthalimide
Phthalimide is a cyclic imide derived from phthalic anhydride, featuring a five-membered imide ring fused to a benzene ring. It falls under HTS 2925.19.91.00 as a carboxyimide-function compound (imide) and its derivative, not specifically named elsewhere in heading 2925. Commonly used as an intermediate in organic synthesis for pharmaceuticals and agrochemicals.
Succinimide
Succinimide is a five-membered cyclic imide derived from succinic anhydride, a simple aliphatic carboxyimide-function compound. Classified under HTS 2925.19.91.00 as an 'other' imide not specifically provided for in prior subheadings. Used in synthesis of pharmaceuticals like ethosuximide and as a reagent in organic chemistry.
Glutarimide
Glutarimide is a six-membered cyclic imide derived from glutaric acid, a carboxyimide-function compound. Falls under HTS 2925.19.91.00 as 'other' imides; used in production of pharmaceuticals like thalidomide analogs and as a corrosion inhibitor.
Maleimide
Maleimide is an unsaturated five-membered cyclic imide with a reactive double bond, used in polymer chemistry and bioconjugation. Classified in HTS 2925.19.91.00 as a derivative imide; the imide function determines classification over unsaturation.
N-Phenylmaleimide
N-Phenylmaleimide is an N-substituted derivative of maleimide with a phenyl group on nitrogen, used in high-performance polymer synthesis. HTS 2925.19.91.00 covers this substituted imide as 'other' derivatives; aryl substitution doesn't change heading.
Diphenylmaleimide
Diphenylmaleimide features two phenyl groups on the imide nitrogen, used in specialty resins and electronics. As a substituted cyclic imide derivative, it properly classifies under HTS 2925.19.91.00 'other' imides.