HS code · 6-digit subheading

HS Code 2933.99 – Heterocyclic compounds; n.e.c. in headings no. 2933

HS code 2933.99 is the 6-digit subheading for heterocyclic compounds, n.e.c. in headings no. 2933. It is used for pyridine derivatives, imidazole compounds, indole derivatives, furan derivatives and thiophene compounds.

What HS 2933.99 covers

This 'basket' HS code covers all other heterocyclic compounds not specifically enumerated in other subheadings of 2933. This makes it an incredibly broad and diverse category, encompassing a vast array of organic chemicals with various ring structures containing carbon and at least one other element (like nitrogen, oxygen, sulfur). These compounds serve as critical intermediates, reagents, and active ingredients across numerous industries, including pharmaceuticals, agrochemicals, dyes, and specialty chemicals. International trade is characterized by a wide range of buyers and sellers, from large chemical conglomerates to small research-focused enterprises. Key aspects include the purity of the compound, its specific application, and compliance with general chemical regulations, as many are novel or niche chemicals.

Covers
  • Pyridine derivatives
  • Imidazole compounds
  • Indole derivatives
  • Furan derivatives
  • Thiophene compounds
  • Quinoline derivatives
  • Pyrrole compounds
Examples
  • Specific research chemicals from TCI Chemicals
  • Alfa Aesar
  • Merck KGaA
  • Sigma-Aldrich custom synthesis intermediates

Codes often confused with 2933.99

Common mistake. This code is often confused with more specific heterocyclic codes like 2933.39 (pyridine compounds) or 2933.49 (quinoline compounds) if the compound's primary ring system is explicitly covered elsewhere.

2933.39Heterocyclic compounds; containing an unfused pyridine ring (whether or not hydrogenated) in the structure, n.e.c. in 2933.32933.49Heterocyclic compounds; containing a quinoline or isoquinoline ring-system (whether or not hydrogenated) in the structure, not further fused, other than levorphanol (INN) and its salts

Top exporters and importers of HS code 293399, 2025

In 2025, the largest exporter of HS code 293399 in UN Comtrade data was Switzerland, with 64% of world exports; the largest importer in UN Comtrade data was Slovenia, with 29% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.

Top exporters 2025 · share of world exports

  1. 1 Switzerland $18.0B
  2. 2 China $3.6B
  3. 3 Ireland $1.3B

World total: $28.0B Reported figures on UN Comtrade ↗

Top importers 2025 · share of world imports

  1. 1 Slovenia $8.6B
  2. 2 Italy $8.3B
  3. 3 United States $1.4B

World total: $29.4B Reported figures on UN Comtrade ↗

How these figures are built

109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).

Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.

Brazil NCM codes for 2933.99 36

Brazil splits HS 2933.99 into 36 NCM codes, Mercosur's 8-digit tariff lines.

  1. 2933.99.1 Containing in the structure an unfused pyrazine ring or indole ring-systems (whether or not hydrogenated), not further fusedCuja estrutura contém um ciclo pirazina não condensado ou ciclos indol (hidrogenados ou não) sem outras condensações Group
  2. 2933.99.11 PyrazinamidePirazinamida
  3. 2933.99.12 Amiloride hydrochlorideCloridrato de amilorida
  4. 2933.99.13 PindololPindolol
  5. 2933.99.19 Other pyrazine or indole ring compoundsOutros
  6. 2933.99.20 Other compounds with a diazepine ringCuja estrutura contém um ciclo diazepina (hidrogenado ou não)
  7. 2933.99.3 Containing an azepine ring (whether or not hydrogenated) in the structureCuja estrutura contém um ciclo azepina (hidrogenado ou não) Group
  8. 2933.99.31 Dibenzazepine (iminostilbene)Dibenzoazepina (iminoestilbeno)
  9. 2933.99.32 CarbamazepineCarbamazepina
  10. 2933.99.33 Clomipramine hydrochlorideCloridrato de clomipramina
  11. 2933.99.34 MolinateMolinate (hexaidroazepin-1-carbotioato de S-etila)
  12. 2933.99.35 HexamethyleneimineHexametilenoimina
  13. 2933.99.39 Other azepine ring compoundsOutros
  14. 2933.99.4 Containing a pyrrole ring (whether or not hydrogenated) in the structureCuja estrutura contém um ciclo pirrol (hidrogenado ou não) Group
  15. 2933.99.41 Clemastine, its derivatives and their saltsClemastina e seus derivados; sais destes produtos
  16. 2933.99.42 AmisulprideAmisulprida
  17. 2933.99.43 SultoprideSultoprida
  18. 2933.99.44 AlizaprideAlizaprida
  19. 2933.99.45 Buflomedil, its derivatives and their saltsBuflomedil e seus derivados; sais destes produtos
  20. 2933.99.46 Enalapril maleateMaleato de enalapril
  21. 2933.99.47 Ketorolac trometamolKetorolac trometamina
  22. 2933.99.49 Other pyrrole ring compoundsOutros
  23. 2933.99.5 Containing an imidazole ring (whether or not hydrogenated) in the structureCuja estrutura contém um ciclo imidazol (hidrogenados ou não) Group
  24. 2933.99.51 BenomylBenomil
  25. 2933.99.52 OxfendazoleOxifendazol
  26. 2933.99.53 Albendazole and its sulphoxideAlbendazol e seu sulfóxido
  27. 2933.99.54 MebendazoleMebendazol
  28. 2933.99.55 FlubendazoleFlubendazol
  29. 2933.99.56 FenbendazoleFembendazol
  30. 2933.99.59 Other fused imidazole ring compoundsOutros
  31. 2933.99.6 Containing an unfused triazole ring (whether or not hydrogenated) in the structureCuja estrutura contém um ciclo triazol (hidrogenado ou não), não condensado Group
  32. 2933.99.61 TriadimenolTriadimenol
  33. 2933.99.62 TriadimefonTriadimefon
  34. 2933.99.63 TriazophosTriazofós (fosforotioato de O,O-dietila O-(1-fenil-1H-1,2,4-triazol-3-ila))
  35. 2933.99.69 Other unfused triazole ring compoundsOutros
  36. 2933.99.9 OtherOutros Group
  37. 2933.99.91 Azinphos-ethylAzinfós etílico
  38. 2933.99.92 Nalidixic acidÁcido nalidíxico
  39. 2933.99.93 ClofazimineClofazimina
  40. 2933.99.95 Amezinium metilsulfateMetilssulfato de amezínio
  41. 2933.99.96 Maleic hydrazide and its saltsHidrazida maleica e seus sais
  42. 2933.99.99 Other nitrogen-only heterocyclic compoundsOutros

All Brazil NCM codes in heading 29.33 →

Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.

Questions about HS 2933.99

What is HS code 293399?

HS code 293399 is a 6-digit subheading in the Harmonized System that covers: Heterocyclic compounds; n.e.c. in headings no. 2933. This 'basket' HS code covers all other heterocyclic compounds not specifically enumerated in other subheadings of 2933. This makes it an incredibly broad and diverse category, encompassing a vast array of organic chemicals with various ring structures containing carbon and at least one other element (like nitrogen, oxygen, sulfur). These compounds serve as critical intermediates, reagents, and active ingredients across numerous industries, including pharmaceuticals, agrochemicals, dyes, and specialty chemicals. International trade is characterized by a wide range of buyers and sellers, from large chemical conglomerates to small research-focused enterprises. Key aspects include the purity of the compound, its specific application, and compliance with general chemical regulations, as many are novel or niche chemicals.

What products fall under HS code 293399?

Pyridine derivatives, Imidazole compounds, Indole derivatives, Furan derivatives, Thiophene compounds, Quinoline derivatives, Pyrrole compounds

What are common misclassifications for HS code 293399?

This code is often confused with more specific heterocyclic codes like 2933.39 (pyridine compounds) or 2933.49 (quinoline compounds) if the compound's primary ring system is explicitly covered elsewhere.

Which countries are the top exporters of goods under HS code 293399?

In 2025, the top exporters of HS code 293399 in UN Comtrade data were Switzerland ($18.0B, 64% of world exports), China ($3.6B) and Ireland ($1.3B). World exports came to about $28.0B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

Which countries are the top importers of goods under HS code 293399?

In 2025, the top importers of HS code 293399 in UN Comtrade data were Slovenia ($8.6B, 29% of world imports), Italy ($8.3B) and the United States ($1.4B). World imports came to about $29.4B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

How is HS code 293399 structured?

HS code 293399 is a 6-digit subheading under the Harmonized System. The first 2 digits (29) identify the chapter, digits 3-4 (33) identify the heading, and digits 5-6 (99) specify the subheading. This code is standardized globally by the World Customs Organization.

What is the Brazil NCM code for HS code 293399?

Brazil splits HS code 293399 into 36 NCM codes: 2933.99.11 (Pyrazinamide), 2933.99.12 (Amiloride hydrochloride), 2933.99.13 (Pindolol), 2933.99.19 (Other pyrazine or indole ring compounds), 2933.99.20 (Other compounds with a diazepine ring), 2933.99.31 (Dibenzazepine (iminostilbene)), 2933.99.32 (Carbamazepine), 2933.99.33 (Clomipramine hydrochloride), and more listed on this page. The first 6 digits of each match the HS code.