N-Phenylmaleimide from Canada
N-Phenylmaleimide is a cyclic imide with carboxyimide-function, but classified here under imine derivatives per Chapter Note 3 (last in numerical order) in HTS 2925.29.90.00. Key Diels-Alder dienophile.
Duty Rate — Canada → United States
110%
Rate breakdown
9903.04.6096.3%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• Submit X-ray crystal structure confirming planar imide ring system
• Declare melting point (88-92°C) and purity by HPLC (>99%)
• Include polymerization inhibitor (hydroquinone) concentration