2917.12 - Adipic acid, its salts and esters:

This HTS category, 2917.12, encompasses adipic acid, along with its various salts and esters. Adipic acid is a dicarboxylic acid, characterized by two carboxyl groups separated by a four-carbon aliphatic chain. Its salts are formed when the acidic hydrogen atoms of the carboxyl groups are replaced by metal ions or ammonium radicals, while esters are formed through the reaction of adipic acid with alcohols. These compounds are primarily white crystalline solids and serve as crucial chemical intermediates.

Distinguishing this category from its siblings, 2917.12 focuses specifically on adipic acid and its derivatives. For instance, while 2917.11.00.00 covers oxalic acid, a simpler dicarboxylic acid, and 2917.13.00 deals with azelaic and sebacic acids (longer chain dicarboxylic acids), this heading exclusively addresses the C6 dicarboxylic acid, adipic acid. Similarly, 2917.14 concerns maleic anhydride, a cyclic anhydride rather than an acyclic dicarboxylic acid.

Within the 2917.12 heading, further subdivisions exist to differentiate between adipic acid itself and other compounds that fall under its salts and esters. The primary subcategory, 2917.12.10.00, is designated for adipic acid in its pure or technical grades. A further, broader subcategory allows for the classification of various salts and esters derived from adipic acid, accommodating the wide range of chemical modifications possible from this foundational molecule.