N,N'-Bis(trimethylsilyl) Urea Technical Grade from Mexico
Technical grade N,N'-Bis(trimethylsilyl) urea (95%+ purity) serves as silylating reagent for carbohydrate protection in nucleoside synthesis. Specifically enumerated in HTS 2931.90.70.00 distinguishing it from general silanes.
Duty Rate — Mexico → United States
10%
Rate breakdown
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
• Technical vs. 99% grades identical classification but purity affects DEA precursor watch lists
• Air-sensitive; requires inert atmosphere packaging certification for import inspection
• Pharma importers need DMF/CEP documentation linking to FDA drug master files