2933.52 - Malonylurea (Barbituric acid) and its salts:

This HTS category, 2933.52, specifically addresses Malonylurea, also known as Barbituric acid, and its various salts. These compounds are characterized by their chemical structure, which features a pyrimidine ring with two carbonyl groups at positions 2 and 4. Barbituric acid itself is a foundational compound in this group, serving as a precursor for a wide range of barbiturate drugs, though this specific HTS code focuses on the un-derivatized acid and its direct salts.

It is important to distinguish this category from its siblings. HTS 2933.53.00.00 enumerates specific named barbiturates, such as phenobarbital and secobarbital, and their salts, which are distinct finished pharmaceutical products. HTS 2933.54.00.00 covers other derivatives of malonylurea that do not fall under the specific list of 2933.53 or the parent category of barbituric acid itself. Furthermore, 2933.55.00.00 deals with a different set of heterocyclic compounds that include specific named drugs.

Within this Malonylurea (Barbituric acid) and its salts category, further distinctions are made through subcategories. 2933.52.10.00 specifically classifies pure or technical grades of Malonylurea (barbituric acid) itself. The residual subcategory, 2933.52.90.00, encompasses all other salts of malonylurea that are not otherwise specified. This hierarchical structure allows for precise classification based on whether the item is the parent compound or a direct salt thereof.