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Heterocyclic compounds with nitrogen hetero-atom(s) only: > Other: > Other: > Other: > Other: > Other
Duty Rate (from China)
Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 to this subchapter
Products classified under HTS 2933.99.97.01
Caffeine Anhydrous Powder
Pure caffeine (1,3,7-trimethylxanthine), a purine alkaloid with a fused pyrimidine-imidazole nitrogen heterocyclic ring system, used in pharmaceuticals and energy supplements. Classified under HTS 2933.99.9701 as a heterocyclic compound with nitrogen hetero-atoms only, not elsewhere specified in heading 2933. Meets Chapter 29 note for separate chemically defined organic compounds.
Nicotine Free Base Liquid
Pure nicotine ((S)-3-(1-methylpyrrolidin-2-yl)pyridine), a pyridine-pyrrolidine bicyclic nitrogen heterocyclic compound used in pharmaceuticals and vaping. Classified in HTS 2933.99.9701 as other nitrogen heterocycles; pyridine ring qualifies despite dual heteroatoms per heading scope.
Imidazole Pharmaceutical Grade
Imidazole (1H-imidazole), a five-membered nitrogen heterocyclic ring compound used as pharmaceutical intermediate and antifungal agent. HTS 2933.99.9701 covers this azole heterocycle with nitrogen hetero-atoms only, not specified elsewhere.
Pyrazole Crystals
Pyrazole (1H-pyrazole), a five-membered aromatic heterocycle with adjacent nitrogen atoms, used in agrochemicals and pharmaceuticals. Falls under HTS 2933.99.9701 as other nitrogen heterocyclic compounds per Chapter 29 scope.
Triazole Technical Grade
1,2,4-Triazole, a five-membered heterocycle with three nitrogen atoms, essential for antifungal drug synthesis like fluconazole. HTS 2933.99.9701 for unspecified nitrogen heterocycles; distinguished from substituted triazoles.
Pyrrole ACS Reagent
Pyrrole (1H-pyrrole), a five-membered nitrogen heterocycle fundamental to porphyrin synthesis and electronics. Classified HTS 2933.99.9701 as other nitrogen hetero-atom compounds; ACS grade for lab use.
Indole-3-Carbaldehyde
Indole-3-carbaldehyde, a bicyclic benzopyrrole with aldehyde substitution, used in perfume and pharma synthesis. HTS 2933.99.9701 as other nitrogen heterocycles; aldehyde function doesn't override per classification notes.
Carbazole Crystals
Carbazole, a tricyclic nitrogen heterocycle used in dyes, electronics, and pharmaceuticals. Pure form classified under HTS 2933.99.9701 as other nitrogen hetero-atom compounds, meeting chemically defined compound criteria.
Phenanthridine
Phenanthridine, a linear tricyclic nitrogen heterocycle used in nucleic acid staining and synthesis. HTS 2933.99.9701 covers this as other nitrogen heterocycles; distinguished from quinoline by fusion pattern.
Pteridine Powder
Pteridine, a fused pyrimido-pyrimidine nitrogen heterocyclic system core to folate and flavin structures. Used in vitamin synthesis; HTS 2933.99.9701 as other nitrogen heterocycles.
Purine Base
Purine (7H-imidazo[4,5-d]pyrimidine), the parent bicyclic nitrogen heterocycle of DNA/RNA bases. HTS 2933.99.9701 for unspecified nitrogen hetero-atom compounds used in biotech.
Acyclovir Active Ingredient
Acyclovir (9-(2-hydroxyethoxymethyl)guanine), synthetic guanine analog with nitrogen heterocyclic purine structure for antiviral medication. Pure API form under HTS 2933.99.9701.
Allopurinol Powder
Allopurinol (1H-pyrazolo[3,4-d]pyrimidin-4-ol), hypoxanthine analog with fused pyrazolo-pyrimidine nitrogen heterocycles for gout treatment. HTS 2933.99.9701 as other.
6-Mercaptopurine
6-Mercaptopurine, a purine analog with thiol substitution used in chemotherapy. Contains only nitrogen hetero-atoms in heterocyclic rings; HTS 2933.99.9701 despite sulfur (not organo-sulfur per note).
Theobromine Powder
Theobromine (3,7-dimethylxanthine), a methylxanthine alkaloid with fused nitrogen-heterocyclic rings, extracted for pharmaceutical and food applications. Falls under HTS 2933.99.9701 as 'other' heterocyclic compounds with nitrogen hetero-atoms only. Excluded from 2939 as it's often supplied in pure form rather than crude alkaloid mixtures.