3,6-Endoxo-1,2,3,6-tetrahydrophthalic anhydride from China
Bicyclic cyclenic anhydride featuring oxygen-bridged norbornene structure with fused phthalic anhydride. Covered by HTS 2917.20.00.00 as cyclenic polycarboxylic acid derivative. Key monomer for high-temperature resistant polymers.
Duty Rate — China → United States
39.2%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Import Tips
• Distinguish exo/endo isomers via NMR; both cyclenic but different reactivity profiles
• Provide Diels-Alder reaction synthesis documentation confirming structure
• Monitor double bond content as full hydrogenation changes to hexahydro version