U.S. exports of Heterocyclic Compounds with Unfused Imidazole Ring (NES) (SITC 51573) totaled $17.8M in August 2026.
Importers of Heterocyclic Compounds with Unfused Imidazole Ring (NES) paid $921K in duties in August 2026, an average duty rate of 8.30% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Heterocyclic Compounds with Unfused Imidazole Ring (NES) imports of $11.1M in August 2026 ran 12% above the year-to-date monthly average of $9.9M.
Last updated: August 2026 dataUnfused imidazole-ring compounds not elsewhere specified are a commercially important class of nitrogen heterocyclics, underpinning a broad range of pharmaceutical APIs, antifungal agents, and ionic liquid precursors. The imidazole scaffold's basicity and hydrogen-bonding capacity make it a preferred pharmacophore in drug design, and several blockbuster antifungals — including azole-class compounds — trace their activity to this ring system. Correct classification requires confirming that the imidazole ring is neither fused nor covered by a more specific SITC subheading such as the hydantoin or benzimidazole categories.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
184 import shipments a month
A benzimidazole has its imidazole ring fused to a benzene ring, forming a bicyclic structure. Compounds with that fused system classify under benzimidazole-specific headings. Standalone, unfused imidazole compounds — where no second ring is joined — fall under this NES category, provided no more specific subheading applies.
Alkylimidazolium salts are among the most widely studied ionic liquids, used as green solvents, electrolytes in energy storage devices, and catalysts in specialty chemical synthesis. Demand from battery technology and green chemistry applications has expanded the commercial footprint of imidazole intermediates beyond traditional pharmaceutical uses.
Basic heading 194 of 465 in section 5
Basic heading 51573 · $17.8M of $26.2B
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ImportsExports
Imports
$11.1MYoY · free account
Exports
$17.8MYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $115.1M of Heterocyclic Compounds with Unfused Imidazole Ring (NES) and exported $133.5M.
Through August 2026. Source: U.S. Census Bureau.
Exports · August 2026
destination
Canada and Japan together take 78% of it.
customs district
Census does not publish district detail for this classification system.
origin
Census does not publish state detail for this classification system.
entry
Census does not publish port detail for this classification system.