Isoindole-1,3-dione from Canada
Isoindole-1,3-dione, a structural isomer of phthalimide, is an aromatic fused-ring lactam with nitrogen hetero-atom. It is imported under HTS 2933.79.1500 as other aromatic lactams for use in resins and dyes. Classification follows Chapter 29's rule for last-in-order heterocyclic nitrogen compounds.
Duty Rate — Canada → United States
100%
Rate breakdown
9903.04.6093.5%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• Cross-reference with phthalimide rulings for consistency; declare exact isomer to avoid generic amide classification