Imidazole-4-Carboxylic Acid from China

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 — China → United States

31.5%

Rate breakdown

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)
9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 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