Piperidine-4-Carboxylic Acid from China
Piperidine-4-carboxylic acid (isonipecotic acid) contains both piperidine ring and carboxylic acid functionality but classifies under HTS 2933.32.5000 per Chapter 29 notes prioritizing heterocyclic structure. Used in synthesis of protease inhibitors.
Duty Rate — China → United States
44%
Rate breakdown
9903.05.3112.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of China, as provided for in U.S. note 52 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
• Include COA specifying free acid form vs salt to prevent classification disputes
• Package under UN 3261 as corrosive solid, pH <2 in aqueous solution
• Pre-register with FDA if destined for pharmaceutical manufacturing