Imidazole-4-Carboxylic Acid from Mexico
Imidazole-4-carboxylic acid is a key intermediate for pharmaceutical synthesis, featuring the unfused imidazole ring required by heading 2933. As an aromatic heterocyclic compound listed in additional U.S. note 3, it imports under HTS 2933.29.35.00.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6093.5%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
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Include synthesis route and impurity profile for downstream pharma validation
• Ensure proper pH adjustment documentation for carboxylic acid handling
• Label with GHS hazard statements for corrosive organic acid properties