HS code · 6-digit subheading

HS Code 2934.91 – Heterocyclic compounds; other heterocyclic compounds, n.e.c. in 2934.1, 2934.2 and 2934.3

HS code 2934.91 is the 6-digit subheading for heterocyclic compounds, other heterocyclic compounds, n.e.c. in 2934.1, 2934.2 and 2934.3. It is used for thiophene derivatives, pyrimidine-2-thiol, 1,3,4-Thiadiazole, 1,2,4-Triazole-3-thiol and benzothiophene.

What HS 2934.91 covers

This residual category covers a broad spectrum of heterocyclic compounds that contain both sulfur and nitrogen atoms in their ring structure, but do not specifically fall under the more defined categories of thiazole, benzothiazole, or phenothiazine ring systems (2934.10, 2934.20, 2934.30). These "other" compounds are diverse, finding applications across pharmaceuticals, agrochemicals, specialty polymers, and advanced materials. Importers are typically countries with strong chemical and pharmaceutical industries, such as China, India, Germany, and the United States, seeking novel intermediates or specialized chemicals for various manufacturing processes. Exporters are global fine chemical producers. Key aspects of their trade include the highly specialized nature of many of these compounds, often produced in smaller batches, and the need for precise chemical identification to ensure correct classification. The market is driven by continuous innovation in chemical synthesis and the demand for new materials with tailored properties.

Covers
  • Thiophene derivatives
  • Pyrimidine-2-thiol
  • 1,3,4-Thiadiazole
  • 1,2,4-Triazole-3-thiol
  • Benzothiophene
  • Dithianes
  • Thiazolidinediones
Examples
  • Rosiglitazone (Avandia component)
  • Pioglitazone (Actos component)
  • Cimetidine (Tagamet precursor)
  • Ranitidine (Zantac precursor)

Codes often confused with 2934.91

Common mistake. This code is a "basket" category and is frequently confused with 2934.99, which is a broader "other" category for all heterocyclic compounds of heading 2934. The distinction lies in whether the compound contains sulfur and nitrogen in the ring, but not specifically the structures of 2934.10, 2934.20, or 2934.30.

2934.99Nucleic acids and their salts, other heterocyclic compounds, n.e.c. in heading number 293429.34Nucleic acids and their salts, whether or not chemically defined; other heterocyclic compounds2934.10Heterocyclic compounds; containing an unfused thiazole ring (whether or not hydrogenated) in the structure2934.20Heterocyclic compounds; containing in the structure, a benzothiazole ring-system (whether or not hydrogenated), not further fused2934.30Heterocyclic compounds; containing in the structure, a phenothiazine ring-system (whether or not hydrogenated), not further fused

Top exporters and importers of HS code 293491, 2025

In 2025, the largest exporter of HS code 293491 in UN Comtrade data was India, with 51% of world exports; the largest importer in UN Comtrade data was France, with 21% 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 India $11M
  2. 2 Italy $2.7M
  3. 3 Slovakia $2.2M

World total: $21M Reported figures on UN Comtrade ↗

Top importers 2025 · share of world imports

  1. 1 France $4.8M
  2. 2 Egypt $4.7M
  3. 3 Chile $1.9M

World total: $23M 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 2934.91 15

Brazil splits HS 2934.91 into 15 NCM codes, Mercosur's 8-digit tariff lines.

  1. 2934.91.1 Aminorex and brotizolam; salts thereofAminorex e brotizolan; sais destes produtos Group
  2. 2934.91.11 Aminorex and its saltsAminorex e seus sais
  3. 2934.91.12 Brotizolam and its saltsBrotizolam e seus sais
  4. 2934.91.2 Clotiazepam, cloxazolam and dextromoramide; salts thereofClotiazepam, cloxazolam e dextromoramida; sais destes produtos Group
  5. 2934.91.21 ClotiazepamClotiazepam
  6. 2934.91.22 CloxazolamCloxazolam
  7. 2934.91.23 DextromoramideDextromoramida
  8. 2934.91.29 Salts of clotiazepam, cloxazolam, dextromoramideOutros
  9. 2934.91.3 Phendimetrazine, phenmetrazine and haloxazolam; salts thereofFendimetrazina, fenmetrazina e haloxazolam; sais destes produtos Group
  10. 2934.91.31 Phendimetrazine and its saltsFendimetrazina e seus sais
  11. 2934.91.32 Phenmetrazine and its saltsFenmetrazina e seus sais
  12. 2934.91.33 Haloxazolam and its saltsHaloxazolam e seus sais
  13. 2934.91.4 Ketazolam and mesocarb; salts thereofKetazolam e mesocarbo; sais destes produtos Group
  14. 2934.91.41 KetazolamKetazolam
  15. 2934.91.42 MesocarbMesocarbo
  16. 2934.91.49 Salts of ketazolam and mesocarbOutros
  17. 2934.91.50 Oxazolam and its saltsOxazolam e seus sais
  18. 2934.91.60 Pemoline and its saltsPemolina e seus sais
  19. 2934.91.70 Sufentanil and its saltsSufentanila e seus sais

All Brazil NCM codes in heading 29.34 →

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

Questions about HS 2934.91

What is HS code 293491?

HS code 293491 is a 6-digit subheading in the Harmonized System that covers: Heterocyclic compounds; other heterocyclic compounds, n.e.c. in 2934.1, 2934.2 and 2934.3. This residual category covers a broad spectrum of heterocyclic compounds that contain both sulfur and nitrogen atoms in their ring structure, but do not specifically fall under the more defined categories of thiazole, benzothiazole, or phenothiazine ring systems (2934.10, 2934.20, 2934.30). These "other" compounds are diverse, finding applications across pharmaceuticals, agrochemicals, specialty polymers, and advanced materials. Importers are typically countries with strong chemical and pharmaceutical industries, such as China, India, Germany, and the United States, seeking novel intermediates or specialized chemicals for various manufacturing processes. Exporters are global fine chemical producers. Key aspects of their trade include the highly specialized nature of many of these compounds, often produced in smaller batches, and the need for precise chemical identification to ensure correct classification. The market is driven by continuous innovation in chemical synthesis and the demand for new materials with tailored properties.

What products fall under HS code 293491?

Thiophene derivatives, Pyrimidine-2-thiol, 1,3,4-Thiadiazole, 1,2,4-Triazole-3-thiol, Benzothiophene, Dithianes, Thiazolidinediones

What are common misclassifications for HS code 293491?

This code is a "basket" category and is frequently confused with 2934.99, which is a broader "other" category for all heterocyclic compounds of heading 2934. The distinction lies in whether the compound contains sulfur and nitrogen in the ring, but not specifically the structures of 2934.10, 2934.20, or 2934.30.

Which countries are the top exporters of goods under HS code 293491?

In 2025, the top exporters of HS code 293491 in UN Comtrade data were India ($11M, 51% of world exports), Italy ($2.7M) and Slovakia ($2.2M). World exports came to about $21M, 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 293491?

In 2025, the top importers of HS code 293491 in UN Comtrade data were France ($4.8M, 21% of world imports), Egypt ($4.7M) and Chile ($1.9M). World imports came to about $23M, 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 293491 structured?

HS code 293491 is a 6-digit subheading under the Harmonized System. The first 2 digits (29) identify the chapter, digits 3-4 (34) identify the heading, and digits 5-6 (91) specify the subheading. This code is standardized globally by the World Customs Organization.

What is the Brazil NCM code for HS code 293491?

Brazil splits HS code 293491 into 15 NCM codes: 2934.91.11 (Aminorex and its salts), 2934.91.12 (Brotizolam and its salts), 2934.91.21 (Clotiazepam), 2934.91.22 (Cloxazolam), 2934.91.23 (Dextromoramide), 2934.91.29 (Salts of clotiazepam, cloxazolam, dextromoramide), 2934.91.31 (Phendimetrazine and its salts), 2934.91.32 (Phenmetrazine and its salts), and more listed on this page. The first 6 digits of each match the HS code.