Thiazole-4-Carboxylic Acid from Mexico
Thiazole-4-carboxylic acid contains an unfused thiazole ring with carboxylic acid substitution at position 4, used in pharmaceutical synthesis. Classified under HTS 2934.10.90.00 as the thiazole ring structure determines heading per Chapter 29 precedence over carboxylic acid classification.
Duty Rate — Mexico → United States
100%
Rate breakdown
9903.04.6093.5%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• Neutralize residual acidity with proper packaging to prevent corrosion
• Provide melting point and titration data confirming carboxylic acid purity
• Declare synthetic intermediates status to expedite pharmaceutical import