2904.99.35.00 - 4,4'-Dinitrostilbene-2,2'-disulfonic acid

This classification encompasses sulfonated, nitrated, or nitrosated derivatives of hydrocarbons that do not fit into the more specific sibling categories within heading 2904. These compounds are characterized by the presence of both sulfonic acid groups (-SO₃H) and nitro groups (-NO₂) attached to a stilbene hydrocarbon structure. The specific compound, 4,4'-Dinitrostilbene-2,2'-disulfonic acid, serves as a key example and is a highly substituted derivative.

Distinguishing this category from its siblings, it is important to note that other headings within 2904.99 cover more narrowly defined sulfonated and/or nitrated hydrocarbons. For instance, sibling categories address specific halogenated nitrotoluenes, nitrotoluenesulfonic acids, and certain halogenated nitrobenzenes. This category, however, is reserved for those derivatives that are not captured by these more specific subheadings, particularly those with a complex structure like the dinitrostilbene disulfonic acid.

As this HTS code represents a leaf node, there are no further subcategories. Classification at this level requires careful examination of the chemical structure to confirm the presence of both sulfonic acid and nitro functionalities on a stilbene backbone, ensuring it is not classifiable under more specific provisions elsewhere in Chapter 29.