2921.51.10.00 - 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate

This classification pertains to aromatic polyamines, specifically ortho-, meta-, and para-phenylenediamines, as well as various diaminotoluenes and their salts. These compounds are characterized by the presence of two or more amine groups attached to an aromatic ring structure, such as benzene or toluene. Their primary applications often lie in the synthesis of dyes, pigments, hair colorants, photographic chemicals, and as intermediates in the production of polymers and pharmaceuticals. The inclusion of their salts accounts for various commercially traded forms where the amine group is protonated.

The distinguishing factor for this category lies in the specific isomers of phenylenediamines and diaminotoluenes covered, as well as their immediate derivatives. While other aromatic amines might be classified elsewhere, this heading focuses on compounds with at least two amine functional groups directly attached to the aromatic nucleus. The presence of methyl groups on the toluene ring differentiates the diaminotoluenes from phenylenediamines.

As this is a leaf node in the HTS classification system, there are no further subcategories. Classification within this heading is determined by the specific chemical identity of the aromatic polyamine or its salt, often confirmed through laboratory analysis or manufacturer's specifications. The official description provides specific examples that fall under this code, guiding classifiers to accurately identify and categorize these substances based on their chemical structure.