2909.50 - Ether-phenols, ether-alcohol-phenols and their halogenated, sulfonated, nitrated or nitrosated derivatives:

This HTS category, 2909.50, encompasses ether-phenols, ether-alcohol-phenols, and their chemically modified derivatives. Ether-phenols are compounds where an ether linkage connects an alkyl or aryl group to a phenol group. Ether-alcohol-phenols, a subset, further incorporate an alcohol group within their structure. The "derivatives" aspect signifies compounds that have undergone halogenation, sulfonation, nitration, or nitrosation, altering the base ether-phenol or ether-alcohol-phenol molecule. These substances find applications in various chemical synthesis processes and as intermediates in the production of pharmaceuticals, resins, and other fine chemicals.

Distinguishing this category from its siblings, 2909.50 specifically focuses on compounds possessing both an ether and a phenol functional group, or an ether, alcohol, and phenol group. It does not include simple acyclic ethers (2909.10), cyclanic, cyclenic, or cycloterpenic ethers (2909.20), or purely aromatic ethers lacking a phenolic hydroxyl group (2909.30). Furthermore, it is distinct from alcohol and ether peroxides and their derivatives (2909.60).

Within this category, the subdivisions recognize specific key compounds and broader groups. 2909.50.10.00 identifies the specific substance 4-Ethylguaiacol, a notable aromatic compound with distinct olfactory properties. 2909.50.20.00 covers Guaiacol and its related derivatives, recognizing the importance of this foundational phenolic ether. Finally, the "Other" subcategory serves as a catch-all for ether-phenols, ether-alcohol-phenols, and their halogenated, sulfonated, nitrated, or nitrosated derivatives that do not fall under the more specific enumerations.