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).
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Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If sulfur directly linked as organo-sulfur compound
Chapter note excludes sulfonated derivatives but pure thiols stay in 2933.
If immunosuppressant serum product
Immunological products excluded to 3002.
If specific purine thiol subheading
Guanine analogs may have statistical breakout.
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Import Tips & Compliance
• Light-sensitive; amber packaging with stability data
• NCI/IMPD documentation for clinical trial material
• Sulfur content analysis to confirm non-organo-sulfur status
Related Products 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.